<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux.git/drivers/usb/typec, branch v5.9-rc4</title>
<subtitle>Linux kernel source tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/'/>
<entry>
<title>Merge tag 'usb-5.9-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb</title>
<updated>2020-08-30T17:51:03+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2020-08-30T17:51:03+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=6f0306d1bfbc4d3e3fcfb949ee2c4af21071920a'/>
<id>6f0306d1bfbc4d3e3fcfb949ee2c4af21071920a</id>
<content type='text'>
Pull USB fixes from Greg KH:
 "Let's try this again...  Here are some USB fixes for 5.9-rc3.

  This differs from the previous pull request for this release in that
  the usb gadget patch now does not break some systems, and actually
  does what it was intended to do. Many thanks to Marek Szyprowski for
  quickly noticing and testing the patch from Andy Shevchenko to resolve
  this issue.

  Additionally, some more new USB quirks have been added to get some new
  devices to work properly based on user reports.

  Other than that, the patches are all here, and they contain:

   - usb gadget driver fixes

   - xhci driver fixes

   - typec fixes

   - new quirks and ids

   - fixes for USB patches that went into 5.9-rc1.

  All of these have been tested in linux-next with no reported issues"

* tag 'usb-5.9-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb: (33 commits)
  usb: storage: Add unusual_uas entry for Sony PSZ drives
  USB: Ignore UAS for JMicron JMS567 ATA/ATAPI Bridge
  usb: host: ohci-exynos: Fix error handling in exynos_ohci_probe()
  USB: gadget: u_f: Unbreak offset calculation in VLAs
  USB: quirks: Ignore duplicate endpoint on Sound Devices MixPre-D
  usb: typec: tcpm: Fix Fix source hard reset response for TDA 2.3.1.1 and TDA 2.3.1.2 failures
  USB: PHY: JZ4770: Fix static checker warning.
  USB: gadget: f_ncm: add bounds checks to ncm_unwrap_ntb()
  USB: gadget: u_f: add overflow checks to VLA macros
  xhci: Always restore EP_SOFT_CLEAR_TOGGLE even if ep reset failed
  xhci: Do warm-reset when both CAS and XDEV_RESUME are set
  usb: host: xhci: fix ep context print mismatch in debugfs
  usb: uas: Add quirk for PNY Pro Elite
  tools: usb: move to tools buildsystem
  USB: Fix device driver race
  USB: Also match device drivers using the -&gt;match vfunc
  usb: host: xhci-tegra: fix tegra_xusb_get_phy()
  usb: host: xhci-tegra: otg usb2/usb3 port init
  usb: hcd: Fix use after free in usb_hcd_pci_remove()
  usb: typec: ucsi: Hold con-&gt;lock for the entire duration of ucsi_register_port()
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull USB fixes from Greg KH:
 "Let's try this again...  Here are some USB fixes for 5.9-rc3.

  This differs from the previous pull request for this release in that
  the usb gadget patch now does not break some systems, and actually
  does what it was intended to do. Many thanks to Marek Szyprowski for
  quickly noticing and testing the patch from Andy Shevchenko to resolve
  this issue.

  Additionally, some more new USB quirks have been added to get some new
  devices to work properly based on user reports.

  Other than that, the patches are all here, and they contain:

   - usb gadget driver fixes

   - xhci driver fixes

   - typec fixes

   - new quirks and ids

   - fixes for USB patches that went into 5.9-rc1.

  All of these have been tested in linux-next with no reported issues"

* tag 'usb-5.9-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb: (33 commits)
  usb: storage: Add unusual_uas entry for Sony PSZ drives
  USB: Ignore UAS for JMicron JMS567 ATA/ATAPI Bridge
  usb: host: ohci-exynos: Fix error handling in exynos_ohci_probe()
  USB: gadget: u_f: Unbreak offset calculation in VLAs
  USB: quirks: Ignore duplicate endpoint on Sound Devices MixPre-D
  usb: typec: tcpm: Fix Fix source hard reset response for TDA 2.3.1.1 and TDA 2.3.1.2 failures
  USB: PHY: JZ4770: Fix static checker warning.
  USB: gadget: f_ncm: add bounds checks to ncm_unwrap_ntb()
  USB: gadget: u_f: add overflow checks to VLA macros
  xhci: Always restore EP_SOFT_CLEAR_TOGGLE even if ep reset failed
  xhci: Do warm-reset when both CAS and XDEV_RESUME are set
  usb: host: xhci: fix ep context print mismatch in debugfs
  usb: uas: Add quirk for PNY Pro Elite
  tools: usb: move to tools buildsystem
  USB: Fix device driver race
  USB: Also match device drivers using the -&gt;match vfunc
  usb: host: xhci-tegra: fix tegra_xusb_get_phy()
  usb: host: xhci-tegra: otg usb2/usb3 port init
  usb: hcd: Fix use after free in usb_hcd_pci_remove()
  usb: typec: ucsi: Hold con-&gt;lock for the entire duration of ucsi_register_port()
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>usb: typec: tcpm: Fix Fix source hard reset response for TDA 2.3.1.1 and TDA 2.3.1.2 failures</title>
<updated>2020-08-25T14:02:35+00:00</updated>
<author>
<name>Badhri Jagan Sridharan</name>
<email>badhri@google.com</email>
</author>
<published>2020-08-17T18:46:01+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=23e26d0577535f5ffe4ff8ed6d06e009553c0bca'/>
<id>23e26d0577535f5ffe4ff8ed6d06e009553c0bca</id>
<content type='text'>
The patch addresses the compliance test failures while running  TDA
2.3.1.1 and  TDA 2.3.1.2 of the "PD Communications Engine USB PD
Compliance MOI" test plan published in https://www.usb.org/usbc.
For a product to be Type-C compliant, it's expected that these tests
are run on usb.org certified Type-C compliance tester as mentioned in
https://www.usb.org/usbc.

While the purpose of TDA 2.3.1.1 and  TDA 2.3.1.2 is to verify that
the static and dynamic electrical capabilities of a Source meet the
requirements for each PDO offered,  while doing so, the tests also
monitor that the timing of the VBUS waveform versus the messages meets
the requirements for Hard Reset defined in PROT-PROC-HR-TSTR as
mentioned in step 11 of TDA.2.3.1.1 and step 15 of TDA.2.3.1.2.

TDB.2.2.13.1: PROT-PROC-HR-TSTR Procedure and Checks for Tester
Originated Hard Reset
Purpose: To perform the appropriate protocol checks relating to any
circumstance in which the Hard Reset signal is sent by the Tester.

UUT is behaving as source:
The Tester sends a Hard Reset signal.
1. Check VBUS stays within present valid voltage range for
tPSHardReset min (25ms) after last bit of Hard Reset signal.
[PROT_PROC_HR_TSTR_1]
2. Check that VBUS starts to fall below present valid voltage range by
tPSHardReset max (35ms). [PROT_PROC_HR_TSTR_2]
3. Check that VBUS reaches vSafe0V within tSafe0v max (650 ms).
[PROT_PROC_HR_TSTR_3]
4. Check that VBUS starts rising to vSafe5V after a delay of
tSrcRecover (0.66s - 1s) from reaching vSafe0V. [PROT_PROC_HR_TSTR_4]
5. Check that VBUS reaches vSafe5V within tSrcTurnOn max (275ms) of
rising above vSafe0v max (0.8V). [PROT_PROC_HR_TSTR_5] Power Delivery
Compliance Plan 139 6. Check that Source Capabilities are finished
sending within tFirstSourceCap max (250ms) of VBUS reaching vSafe5v
min. [PROT_PROC_HR_TSTR_6].

This is in line with 7.1.5 Response to Hard Resets of the USB Power
Delivery Specification Revision 3.0, Version 1.2,
"Hard Reset Signaling indicates a communication failure has occurred
and the Source Shall stop driving VCONN, Shall remove Rp from the
VCONN pin and Shall drive VBUS to vSafe0V as shown in Figure 7-9. The
USB connection May reset during a Hard Reset since the VBUS voltage
will be less than vSafe5V for an extended period of time. After
establishing the vSafe0V voltage condition on VBUS, the Source Shall
wait tSrcRecover before re-applying VCONN and restoring VBUS to
vSafe5V. A Source Shall conform to the VCONN timing as specified in
[USB Type-C 1.3]."

With the above guidelines from the spec in mind, TCPM does not turn
off VCONN while entering SRC_HARD_RESET_VBUS_OFF. The patch makes TCPM
turn off VCONN while entering SRC_HARD_RESET_VBUS_OFF and turn it back
on while entering SRC_HARD_RESET_VBUS_ON along with vbus instead of
having VCONN on through hardreset.

Also, the spec clearly states that "After establishing the vSafe0V
voltage condition on VBUS",  the Source Shall wait tSrcRecover before
re-applying VCONN and restoring VBUS to vSafe5V.
TCPM does not conform to this requirement. If the TCPC driver calls
tcpm_vbus_change with vbus off signal, TCPM right away enters
SRC_HARD_RESET_VBUS_ON without waiting for tSrcRecover.
For TCPC's which are buggy/does not call tcpm_vbus_change, TCPM
assumes that the vsafe0v is instantaneous as TCPM only waits
tSrcRecover instead of waiting for tSafe0v + tSrcRecover.
This patch also fixes this behavior by making sure that TCPM waits for
tSrcRecover before transitioning into SRC_HARD_RESET_VBUS_ON when
tcpm_vbus_change is called by TCPC.
When TCPC does not call tcpm_vbus_change, TCPM assumes the worst case
i.e.  tSafe0v + tSrcRecover before transitioning into
SRC_HARD_RESET_VBUS_ON.

Signed-off-by: Badhri Jagan Sridharan &lt;badhri@google.com&gt;
Reviewed-by: Guenter Roeck &lt;linux@roeck-us.net&gt;
Reviewed-by: Heikki Krogerus &lt;heikki.krogerus@linux.intel.com&gt;
Cc: stable &lt;stable@kernel.org&gt;
Link: https://lore.kernel.org/r/20200817184601.1899929-1-badhri@google.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The patch addresses the compliance test failures while running  TDA
2.3.1.1 and  TDA 2.3.1.2 of the "PD Communications Engine USB PD
Compliance MOI" test plan published in https://www.usb.org/usbc.
For a product to be Type-C compliant, it's expected that these tests
are run on usb.org certified Type-C compliance tester as mentioned in
https://www.usb.org/usbc.

While the purpose of TDA 2.3.1.1 and  TDA 2.3.1.2 is to verify that
the static and dynamic electrical capabilities of a Source meet the
requirements for each PDO offered,  while doing so, the tests also
monitor that the timing of the VBUS waveform versus the messages meets
the requirements for Hard Reset defined in PROT-PROC-HR-TSTR as
mentioned in step 11 of TDA.2.3.1.1 and step 15 of TDA.2.3.1.2.

TDB.2.2.13.1: PROT-PROC-HR-TSTR Procedure and Checks for Tester
Originated Hard Reset
Purpose: To perform the appropriate protocol checks relating to any
circumstance in which the Hard Reset signal is sent by the Tester.

UUT is behaving as source:
The Tester sends a Hard Reset signal.
1. Check VBUS stays within present valid voltage range for
tPSHardReset min (25ms) after last bit of Hard Reset signal.
[PROT_PROC_HR_TSTR_1]
2. Check that VBUS starts to fall below present valid voltage range by
tPSHardReset max (35ms). [PROT_PROC_HR_TSTR_2]
3. Check that VBUS reaches vSafe0V within tSafe0v max (650 ms).
[PROT_PROC_HR_TSTR_3]
4. Check that VBUS starts rising to vSafe5V after a delay of
tSrcRecover (0.66s - 1s) from reaching vSafe0V. [PROT_PROC_HR_TSTR_4]
5. Check that VBUS reaches vSafe5V within tSrcTurnOn max (275ms) of
rising above vSafe0v max (0.8V). [PROT_PROC_HR_TSTR_5] Power Delivery
Compliance Plan 139 6. Check that Source Capabilities are finished
sending within tFirstSourceCap max (250ms) of VBUS reaching vSafe5v
min. [PROT_PROC_HR_TSTR_6].

This is in line with 7.1.5 Response to Hard Resets of the USB Power
Delivery Specification Revision 3.0, Version 1.2,
"Hard Reset Signaling indicates a communication failure has occurred
and the Source Shall stop driving VCONN, Shall remove Rp from the
VCONN pin and Shall drive VBUS to vSafe0V as shown in Figure 7-9. The
USB connection May reset during a Hard Reset since the VBUS voltage
will be less than vSafe5V for an extended period of time. After
establishing the vSafe0V voltage condition on VBUS, the Source Shall
wait tSrcRecover before re-applying VCONN and restoring VBUS to
vSafe5V. A Source Shall conform to the VCONN timing as specified in
[USB Type-C 1.3]."

With the above guidelines from the spec in mind, TCPM does not turn
off VCONN while entering SRC_HARD_RESET_VBUS_OFF. The patch makes TCPM
turn off VCONN while entering SRC_HARD_RESET_VBUS_OFF and turn it back
on while entering SRC_HARD_RESET_VBUS_ON along with vbus instead of
having VCONN on through hardreset.

Also, the spec clearly states that "After establishing the vSafe0V
voltage condition on VBUS",  the Source Shall wait tSrcRecover before
re-applying VCONN and restoring VBUS to vSafe5V.
TCPM does not conform to this requirement. If the TCPC driver calls
tcpm_vbus_change with vbus off signal, TCPM right away enters
SRC_HARD_RESET_VBUS_ON without waiting for tSrcRecover.
For TCPC's which are buggy/does not call tcpm_vbus_change, TCPM
assumes that the vsafe0v is instantaneous as TCPM only waits
tSrcRecover instead of waiting for tSafe0v + tSrcRecover.
This patch also fixes this behavior by making sure that TCPM waits for
tSrcRecover before transitioning into SRC_HARD_RESET_VBUS_ON when
tcpm_vbus_change is called by TCPC.
When TCPC does not call tcpm_vbus_change, TCPM assumes the worst case
i.e.  tSafe0v + tSrcRecover before transitioning into
SRC_HARD_RESET_VBUS_ON.

Signed-off-by: Badhri Jagan Sridharan &lt;badhri@google.com&gt;
Reviewed-by: Guenter Roeck &lt;linux@roeck-us.net&gt;
Reviewed-by: Heikki Krogerus &lt;heikki.krogerus@linux.intel.com&gt;
Cc: stable &lt;stable@kernel.org&gt;
Link: https://lore.kernel.org/r/20200817184601.1899929-1-badhri@google.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>treewide: Use fallthrough pseudo-keyword</title>
<updated>2020-08-23T22:36:59+00:00</updated>
<author>
<name>Gustavo A. R. Silva</name>
<email>gustavoars@kernel.org</email>
</author>
<published>2020-08-23T22:36:59+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=df561f6688fef775baa341a0f5d960becd248b11'/>
<id>df561f6688fef775baa341a0f5d960becd248b11</id>
<content type='text'>
Replace the existing /* fall through */ comments and its variants with
the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary
fall-through markings when it is the case.

[1] https://www.kernel.org/doc/html/v5.7/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through

Signed-off-by: Gustavo A. R. Silva &lt;gustavoars@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Replace the existing /* fall through */ comments and its variants with
the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary
fall-through markings when it is the case.

[1] https://www.kernel.org/doc/html/v5.7/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through

Signed-off-by: Gustavo A. R. Silva &lt;gustavoars@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>usb: typec: ucsi: Hold con-&gt;lock for the entire duration of ucsi_register_port()</title>
<updated>2020-08-18T10:08:51+00:00</updated>
<author>
<name>Hans de Goede</name>
<email>hdegoede@redhat.com</email>
</author>
<published>2020-08-09T14:19:04+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=bed97b30968ba354035a020989df0623e52b5536'/>
<id>bed97b30968ba354035a020989df0623e52b5536</id>
<content type='text'>
Commit 081da1325d35 ("usb: typec: ucsi: displayport: Fix a potential race
during registration") made the ucsi code hold con-&gt;lock in
ucsi_register_displayport(). But we really don't want any interactions
with the connector to run before the port-registration process is fully
complete.

This commit moves the taking of con-&gt;lock from ucsi_register_displayport()
into ucsi_register_port() to achieve this.

Cc: stable@vger.kernel.org
Fixes: 081da1325d35 ("usb: typec: ucsi: displayport: Fix a potential race during registration")
Signed-off-by: Hans de Goede &lt;hdegoede@redhat.com&gt;
Acked-by: Heikki Krogerus &lt;heikki.krogerus@linux.intel.com&gt;
Reviewed-by: Guenter Roeck &lt;linux@roeck-us.net&gt;
Link: https://lore.kernel.org/r/20200809141904.4317-5-hdegoede@redhat.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Commit 081da1325d35 ("usb: typec: ucsi: displayport: Fix a potential race
during registration") made the ucsi code hold con-&gt;lock in
ucsi_register_displayport(). But we really don't want any interactions
with the connector to run before the port-registration process is fully
complete.

This commit moves the taking of con-&gt;lock from ucsi_register_displayport()
into ucsi_register_port() to achieve this.

Cc: stable@vger.kernel.org
Fixes: 081da1325d35 ("usb: typec: ucsi: displayport: Fix a potential race during registration")
Signed-off-by: Hans de Goede &lt;hdegoede@redhat.com&gt;
Acked-by: Heikki Krogerus &lt;heikki.krogerus@linux.intel.com&gt;
Reviewed-by: Guenter Roeck &lt;linux@roeck-us.net&gt;
Link: https://lore.kernel.org/r/20200809141904.4317-5-hdegoede@redhat.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>usb: typec: ucsi: Rework ppm_lock handling</title>
<updated>2020-08-18T10:08:44+00:00</updated>
<author>
<name>Hans de Goede</name>
<email>hdegoede@redhat.com</email>
</author>
<published>2020-08-09T14:19:03+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=25794e3079d2a98547b6bf5764ef0240aa89b798'/>
<id>25794e3079d2a98547b6bf5764ef0240aa89b798</id>
<content type='text'>
The ppm_lock really only needs to be hold during 2 functions:
ucsi_reset_ppm() and ucsi_run_command().

Push the taking of the lock down into these 2 functions, renaming
ucsi_run_command() to ucsi_send_command() which was an existing
wrapper already taking the lock for its callers.

This simplifies things for the callers and removes the difference
between ucsi_send_command() and ucsi_run_command() which has led
to various locking bugs in the past.

Cc: stable@vger.kernel.org
Signed-off-by: Hans de Goede &lt;hdegoede@redhat.com&gt;
Acked-by: Heikki Krogerus &lt;heikki.krogerus@linux.intel.com&gt;
Reviewed-by: Guenter Roeck &lt;linux@roeck-us.net&gt;
Link: https://lore.kernel.org/r/20200809141904.4317-4-hdegoede@redhat.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The ppm_lock really only needs to be hold during 2 functions:
ucsi_reset_ppm() and ucsi_run_command().

Push the taking of the lock down into these 2 functions, renaming
ucsi_run_command() to ucsi_send_command() which was an existing
wrapper already taking the lock for its callers.

This simplifies things for the callers and removes the difference
between ucsi_send_command() and ucsi_run_command() which has led
to various locking bugs in the past.

Cc: stable@vger.kernel.org
Signed-off-by: Hans de Goede &lt;hdegoede@redhat.com&gt;
Acked-by: Heikki Krogerus &lt;heikki.krogerus@linux.intel.com&gt;
Reviewed-by: Guenter Roeck &lt;linux@roeck-us.net&gt;
Link: https://lore.kernel.org/r/20200809141904.4317-4-hdegoede@redhat.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>usb: typec: ucsi: Fix 2 unlocked ucsi_run_command calls</title>
<updated>2020-08-18T10:07:42+00:00</updated>
<author>
<name>Hans de Goede</name>
<email>hdegoede@redhat.com</email>
</author>
<published>2020-08-09T14:19:02+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=7e90057f125c8c852940b848e06e7a72f050fc6f'/>
<id>7e90057f125c8c852940b848e06e7a72f050fc6f</id>
<content type='text'>
Fix 2 unlocked ucsi_run_command calls:

1. ucsi_handle_connector_change() contains one ucsi_send_command() call,
which takes the ppm_lock for it; and one ucsi_run_command() call which
relies on the caller have taking the ppm_lock.
ucsi_handle_connector_change() does not take the lock, so the
second (ucsi_run_command) calls should also be ucsi_send_command().

2. ucsi_get_pdos() gets called from ucsi_handle_connector_change() which
does not hold the ppm_lock, so it also must use ucsi_send_command().

This commit also adds a WARN_ON(!mutex_is_locked(&amp;ucsi-&gt;ppm_lock)); to
ucsi_run_command() to avoid similar problems getting re-introduced in
the future.

Cc: stable@vger.kernel.org
Signed-off-by: Hans de Goede &lt;hdegoede@redhat.com&gt;
Acked-by: Heikki Krogerus &lt;heikki.krogerus@linux.intel.com&gt;
Reviewed-by: Guenter Roeck &lt;linux@roeck-us.net&gt;
Link: https://lore.kernel.org/r/20200809141904.4317-3-hdegoede@redhat.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Fix 2 unlocked ucsi_run_command calls:

1. ucsi_handle_connector_change() contains one ucsi_send_command() call,
which takes the ppm_lock for it; and one ucsi_run_command() call which
relies on the caller have taking the ppm_lock.
ucsi_handle_connector_change() does not take the lock, so the
second (ucsi_run_command) calls should also be ucsi_send_command().

2. ucsi_get_pdos() gets called from ucsi_handle_connector_change() which
does not hold the ppm_lock, so it also must use ucsi_send_command().

This commit also adds a WARN_ON(!mutex_is_locked(&amp;ucsi-&gt;ppm_lock)); to
ucsi_run_command() to avoid similar problems getting re-introduced in
the future.

Cc: stable@vger.kernel.org
Signed-off-by: Hans de Goede &lt;hdegoede@redhat.com&gt;
Acked-by: Heikki Krogerus &lt;heikki.krogerus@linux.intel.com&gt;
Reviewed-by: Guenter Roeck &lt;linux@roeck-us.net&gt;
Link: https://lore.kernel.org/r/20200809141904.4317-3-hdegoede@redhat.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>usb: typec: ucsi: Fix AB BA lock inversion</title>
<updated>2020-08-18T10:07:42+00:00</updated>
<author>
<name>Hans de Goede</name>
<email>hdegoede@redhat.com</email>
</author>
<published>2020-08-09T14:19:01+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=0ff0705a2ef2929e9326c95df48bdbebb0dafaad'/>
<id>0ff0705a2ef2929e9326c95df48bdbebb0dafaad</id>
<content type='text'>
Lockdep reports an AB BA lock inversion between ucsi_init() and
ucsi_handle_connector_change():

AB order:

1. ucsi_init takes ucsi-&gt;ppm_lock (it runs with that locked for the
   duration of the function)
2. usci_init eventually end up calling ucsi_register_displayport,
   which takes ucsi_connector-&gt;lock

BA order:

1. ucsi_handle_connector_change work is started, takes ucsi_connector-&gt;lock
2. ucsi_handle_connector_change calls ucsi_send_command which takes
   ucsi-&gt;ppm_lock

The ppm_lock really only needs to be hold during 2 functions:
ucsi_reset_ppm() and ucsi_run_command().

This commit fixes the AB BA lock inversion by making ucsi_init drop the
ucsi-&gt;ppm_lock before it starts registering ports; and replacing any
ucsi_run_command() calls after this point with ucsi_send_command()
(which is a wrapper around run_command taking the lock while handling
the command).

Some of the replacing of ucsi_run_command with ucsi_send_command
in the helpers used during port registration also fixes a number of
code paths after registration which call ucsi_run_command() without
holding the ppm_lock:
1. ucsi_altmode_update_active() call in ucsi/displayport.c
2. ucsi_register_altmodes() call from ucsi_handle_connector_change()
   (through ucsi_partner_change())

Cc: stable@vger.kernel.org
Signed-off-by: Hans de Goede &lt;hdegoede@redhat.com&gt;
Acked-by: Heikki Krogerus &lt;heikki.krogerus@linux.intel.com&gt;
Reviewed-by: Guenter Roeck &lt;linux@roeck-us.net&gt;
Link: https://lore.kernel.org/r/20200809141904.4317-2-hdegoede@redhat.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Lockdep reports an AB BA lock inversion between ucsi_init() and
ucsi_handle_connector_change():

AB order:

1. ucsi_init takes ucsi-&gt;ppm_lock (it runs with that locked for the
   duration of the function)
2. usci_init eventually end up calling ucsi_register_displayport,
   which takes ucsi_connector-&gt;lock

BA order:

1. ucsi_handle_connector_change work is started, takes ucsi_connector-&gt;lock
2. ucsi_handle_connector_change calls ucsi_send_command which takes
   ucsi-&gt;ppm_lock

The ppm_lock really only needs to be hold during 2 functions:
ucsi_reset_ppm() and ucsi_run_command().

This commit fixes the AB BA lock inversion by making ucsi_init drop the
ucsi-&gt;ppm_lock before it starts registering ports; and replacing any
ucsi_run_command() calls after this point with ucsi_send_command()
(which is a wrapper around run_command taking the lock while handling
the command).

Some of the replacing of ucsi_run_command with ucsi_send_command
in the helpers used during port registration also fixes a number of
code paths after registration which call ucsi_run_command() without
holding the ppm_lock:
1. ucsi_altmode_update_active() call in ucsi/displayport.c
2. ucsi_register_altmodes() call from ucsi_handle_connector_change()
   (through ucsi_partner_change())

Cc: stable@vger.kernel.org
Signed-off-by: Hans de Goede &lt;hdegoede@redhat.com&gt;
Acked-by: Heikki Krogerus &lt;heikki.krogerus@linux.intel.com&gt;
Reviewed-by: Guenter Roeck &lt;linux@roeck-us.net&gt;
Link: https://lore.kernel.org/r/20200809141904.4317-2-hdegoede@redhat.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>usb: typec: tcpm: Add WARN_ON ensure we are not trying to send 2 VDM packets at the same time</title>
<updated>2020-07-29T12:11:05+00:00</updated>
<author>
<name>Hans de Goede</name>
<email>hdegoede@redhat.com</email>
</author>
<published>2020-07-24T17:47:02+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=754498c1d6369d47b6433e9a05ba926255c2d699'/>
<id>754498c1d6369d47b6433e9a05ba926255c2d699</id>
<content type='text'>
The tcpm.c code for sending VDMs assumes that there will only be one VDM
in flight at the time. The "queue" used by tcpm_queue_vdm is only 1 entry
deep.

This assumes that the higher layers (tcpm state-machine and alt-mode
drivers) ensure that queuing a new VDM before the old one has been
completely send (or it timed out) add a WARN_ON to check for this.

Reviewed-by: Heikki Krogerus &lt;heikki.krogerus@linux.intel.com&gt;
Reviewed-by: Guenter Roeck &lt;linux@roeck-us.net&gt;
Signed-off-by: Hans de Goede &lt;hdegoede@redhat.com&gt;
Link: https://lore.kernel.org/r/20200724174702.61754-6-hdegoede@redhat.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The tcpm.c code for sending VDMs assumes that there will only be one VDM
in flight at the time. The "queue" used by tcpm_queue_vdm is only 1 entry
deep.

This assumes that the higher layers (tcpm state-machine and alt-mode
drivers) ensure that queuing a new VDM before the old one has been
completely send (or it timed out) add a WARN_ON to check for this.

Reviewed-by: Heikki Krogerus &lt;heikki.krogerus@linux.intel.com&gt;
Reviewed-by: Guenter Roeck &lt;linux@roeck-us.net&gt;
Signed-off-by: Hans de Goede &lt;hdegoede@redhat.com&gt;
Link: https://lore.kernel.org/r/20200724174702.61754-6-hdegoede@redhat.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>usb: typec: tcpm: Fix AB BA lock inversion between tcpm code and the alt-mode drivers</title>
<updated>2020-07-29T12:11:05+00:00</updated>
<author>
<name>Hans de Goede</name>
<email>hdegoede@redhat.com</email>
</author>
<published>2020-07-24T17:47:01+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=a37241d83465dbcb1981093e139701a0755156e3'/>
<id>a37241d83465dbcb1981093e139701a0755156e3</id>
<content type='text'>
When we receive a PD data packet which ends up being for the alt-mode
driver we have the following lock order:

1. tcpm_pd_rx_handler take the tcpm-port lock
2. We call into the alt-mode driver which takes the alt-mode's lock

And when the alt-mode driver initiates communication we have the following
lock order:

3. alt-mode driver takes the alt-mode's lock
4. alt-mode driver calls tcpm_altmode_enter which takes the tcpm-port lock

This is a classic AB BA lock inversion issue.

With the refactoring of tcpm_handle_vdm_request() done before this patch,
we don't rely on, or need to make changes to the tcpm-port data by the
time we make call 2. from above. All data to be passed to the alt-mode
driver sits on our stack at this point, and thus does not need locking.

So after the refactoring we can simply fix this by releasing the
tcpm-port lock before calling into the alt-mode driver.

This fixes the following lockdep warning:

[  191.454238] ======================================================
[  191.454240] WARNING: possible circular locking dependency detected
[  191.454244] 5.8.0-rc5+ #1 Not tainted
[  191.454246] ------------------------------------------------------
[  191.454248] kworker/u8:5/794 is trying to acquire lock:
[  191.454251] ffff9bac8e30d4a8 (&amp;dp-&gt;lock){+.+.}-{3:3}, at: dp_altmode_vdm+0x30/0xf0 [typec_displayport]
[  191.454263]
               but task is already holding lock:
[  191.454264] ffff9bac9dc240a0 (&amp;port-&gt;lock#2){+.+.}-{3:3}, at: tcpm_pd_rx_handler+0x43/0x12c0 [tcpm]
[  191.454273]
               which lock already depends on the new lock.

[  191.454275]
               the existing dependency chain (in reverse order) is:
[  191.454277]
               -&gt; #1 (&amp;port-&gt;lock#2){+.+.}-{3:3}:
[  191.454286]        __mutex_lock+0x7b/0x820
[  191.454290]        tcpm_altmode_enter+0x23/0x90 [tcpm]
[  191.454293]        dp_altmode_work+0xca/0xe0 [typec_displayport]
[  191.454299]        process_one_work+0x23f/0x570
[  191.454302]        worker_thread+0x55/0x3c0
[  191.454305]        kthread+0x138/0x160
[  191.454309]        ret_from_fork+0x22/0x30
[  191.454311]
               -&gt; #0 (&amp;dp-&gt;lock){+.+.}-{3:3}:
[  191.454317]        __lock_acquire+0x1241/0x2090
[  191.454320]        lock_acquire+0xa4/0x3d0
[  191.454323]        __mutex_lock+0x7b/0x820
[  191.454326]        dp_altmode_vdm+0x30/0xf0 [typec_displayport]
[  191.454330]        tcpm_pd_rx_handler+0x11ae/0x12c0 [tcpm]
[  191.454333]        process_one_work+0x23f/0x570
[  191.454336]        worker_thread+0x55/0x3c0
[  191.454338]        kthread+0x138/0x160
[  191.454341]        ret_from_fork+0x22/0x30
[  191.454343]
               other info that might help us debug this:

[  191.454345]  Possible unsafe locking scenario:

[  191.454347]        CPU0                    CPU1
[  191.454348]        ----                    ----
[  191.454350]   lock(&amp;port-&gt;lock#2);
[  191.454353]                                lock(&amp;dp-&gt;lock);
[  191.454355]                                lock(&amp;port-&gt;lock#2);
[  191.454357]   lock(&amp;dp-&gt;lock);
[  191.454360]
                *** DEADLOCK ***

Reviewed-by: Heikki Krogerus &lt;heikki.krogerus@linux.intel.com&gt;
Reviewed-by: Guenter Roeck &lt;linux@roeck-us.net&gt;
Signed-off-by: Hans de Goede &lt;hdegoede@redhat.com&gt;
Link: https://lore.kernel.org/r/20200724174702.61754-5-hdegoede@redhat.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
When we receive a PD data packet which ends up being for the alt-mode
driver we have the following lock order:

1. tcpm_pd_rx_handler take the tcpm-port lock
2. We call into the alt-mode driver which takes the alt-mode's lock

And when the alt-mode driver initiates communication we have the following
lock order:

3. alt-mode driver takes the alt-mode's lock
4. alt-mode driver calls tcpm_altmode_enter which takes the tcpm-port lock

This is a classic AB BA lock inversion issue.

With the refactoring of tcpm_handle_vdm_request() done before this patch,
we don't rely on, or need to make changes to the tcpm-port data by the
time we make call 2. from above. All data to be passed to the alt-mode
driver sits on our stack at this point, and thus does not need locking.

So after the refactoring we can simply fix this by releasing the
tcpm-port lock before calling into the alt-mode driver.

This fixes the following lockdep warning:

[  191.454238] ======================================================
[  191.454240] WARNING: possible circular locking dependency detected
[  191.454244] 5.8.0-rc5+ #1 Not tainted
[  191.454246] ------------------------------------------------------
[  191.454248] kworker/u8:5/794 is trying to acquire lock:
[  191.454251] ffff9bac8e30d4a8 (&amp;dp-&gt;lock){+.+.}-{3:3}, at: dp_altmode_vdm+0x30/0xf0 [typec_displayport]
[  191.454263]
               but task is already holding lock:
[  191.454264] ffff9bac9dc240a0 (&amp;port-&gt;lock#2){+.+.}-{3:3}, at: tcpm_pd_rx_handler+0x43/0x12c0 [tcpm]
[  191.454273]
               which lock already depends on the new lock.

[  191.454275]
               the existing dependency chain (in reverse order) is:
[  191.454277]
               -&gt; #1 (&amp;port-&gt;lock#2){+.+.}-{3:3}:
[  191.454286]        __mutex_lock+0x7b/0x820
[  191.454290]        tcpm_altmode_enter+0x23/0x90 [tcpm]
[  191.454293]        dp_altmode_work+0xca/0xe0 [typec_displayport]
[  191.454299]        process_one_work+0x23f/0x570
[  191.454302]        worker_thread+0x55/0x3c0
[  191.454305]        kthread+0x138/0x160
[  191.454309]        ret_from_fork+0x22/0x30
[  191.454311]
               -&gt; #0 (&amp;dp-&gt;lock){+.+.}-{3:3}:
[  191.454317]        __lock_acquire+0x1241/0x2090
[  191.454320]        lock_acquire+0xa4/0x3d0
[  191.454323]        __mutex_lock+0x7b/0x820
[  191.454326]        dp_altmode_vdm+0x30/0xf0 [typec_displayport]
[  191.454330]        tcpm_pd_rx_handler+0x11ae/0x12c0 [tcpm]
[  191.454333]        process_one_work+0x23f/0x570
[  191.454336]        worker_thread+0x55/0x3c0
[  191.454338]        kthread+0x138/0x160
[  191.454341]        ret_from_fork+0x22/0x30
[  191.454343]
               other info that might help us debug this:

[  191.454345]  Possible unsafe locking scenario:

[  191.454347]        CPU0                    CPU1
[  191.454348]        ----                    ----
[  191.454350]   lock(&amp;port-&gt;lock#2);
[  191.454353]                                lock(&amp;dp-&gt;lock);
[  191.454355]                                lock(&amp;port-&gt;lock#2);
[  191.454357]   lock(&amp;dp-&gt;lock);
[  191.454360]
                *** DEADLOCK ***

Reviewed-by: Heikki Krogerus &lt;heikki.krogerus@linux.intel.com&gt;
Reviewed-by: Guenter Roeck &lt;linux@roeck-us.net&gt;
Signed-off-by: Hans de Goede &lt;hdegoede@redhat.com&gt;
Link: https://lore.kernel.org/r/20200724174702.61754-5-hdegoede@redhat.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>usb: typec: tcpm: Refactor tcpm_handle_vdm_request</title>
<updated>2020-07-29T12:11:05+00:00</updated>
<author>
<name>Hans de Goede</name>
<email>hdegoede@redhat.com</email>
</author>
<published>2020-07-24T17:47:00+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=95b4d51c96a87cd760c2a4f27fb28a59a27b6368'/>
<id>95b4d51c96a87cd760c2a4f27fb28a59a27b6368</id>
<content type='text'>
Refactor tcpm_handle_vdm_request and its tcpm_pd_svdm helper function so
that reporting the results of the vdm to the altmode-driver is separated
out into a clear separate step inside tcpm_handle_vdm_request, instead
of being scattered over various places inside the tcpm_pd_svdm helper.

This is a preparation patch for fixing an AB BA lock inversion between the
tcpm code and some altmode drivers.

Reviewed-by: Heikki Krogerus &lt;heikki.krogerus@linux.intel.com&gt;
Reviewed-by: Guenter Roeck &lt;linux@roeck-us.net&gt;
Signed-off-by: Hans de Goede &lt;hdegoede@redhat.com&gt;
Link: https://lore.kernel.org/r/20200724174702.61754-4-hdegoede@redhat.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Refactor tcpm_handle_vdm_request and its tcpm_pd_svdm helper function so
that reporting the results of the vdm to the altmode-driver is separated
out into a clear separate step inside tcpm_handle_vdm_request, instead
of being scattered over various places inside the tcpm_pd_svdm helper.

This is a preparation patch for fixing an AB BA lock inversion between the
tcpm code and some altmode drivers.

Reviewed-by: Heikki Krogerus &lt;heikki.krogerus@linux.intel.com&gt;
Reviewed-by: Guenter Roeck &lt;linux@roeck-us.net&gt;
Signed-off-by: Hans de Goede &lt;hdegoede@redhat.com&gt;
Link: https://lore.kernel.org/r/20200724174702.61754-4-hdegoede@redhat.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
</feed>
