linux-stable.git/drivers/net/ipa, branch linux-5.16.y

net: ipa: add an interconnect dependency

2022-03-08T18:14:09+00:00

commit 1dba41c9d2e2dc94b543394974f63d55aa195bfe upstream.

In order to function, the IPA driver very clearly requires the
interconnect framework to be enabled in the kernel configuration.
State that dependency in the Kconfig file.

This became a problem when CONFIG_COMPILE_TEST support was added.
Non-Qualcomm platforms won't necessarily enable CONFIG_INTERCONNECT.

Reported-by: kernel test robot 
Fixes: 38a4066f593c5 ("net: ipa: support COMPILE_TEST")
Signed-off-by: Alex Elder 
Link: https://lore.kernel.org/r/20220301113440.257916-1-elder@linaro.org
Signed-off-by: Jakub Kicinski 
Signed-off-by: Greg Kroah-Hartman

net: ipa: fix a build dependency

2022-03-08T18:14:09+00:00

commit caef14b7530c065fb85d54492768fa48fdb5093e upstream.

An IPA build problem arose in the linux-next tree the other day.
The problem is that a recent commit adds a new dependency on some
code, and the Kconfig file for IPA doesn't reflect that dependency.
As a result, some configurations can fail to build (particularly
when COMPILE_TEST is enabled).

The recent patch adds calls to qmp_get(), qmp_put(), and qmp_send(),
and those are built based on the QCOM_AOSS_QMP config option.  If
that symbol is not defined, stubs are defined, so we just need to
ensure QCOM_AOSS_QMP is compatible with QCOM_IPA, or it's not
defined.

Reported-by: Randy Dunlap 
Fixes: 34a081761e4e3 ("net: ipa: request IPA register values be retained")
Signed-off-by: Alex Elder 
Tested-by: Randy Dunlap 
Acked-by: Randy Dunlap 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

net: ipa: request IPA register values be retained

2022-02-05T11:39:57+00:00

commit 34a081761e4e3c35381cbfad609ebae2962fe2f8 upstream.

In some cases, the IPA hardware needs to request the always-on
subsystem (AOSS) to coordinate with the IPA microcontroller to
retain IPA register values at power collapse.  This is done by
issuing a QMP request to the AOSS microcontroller.  A similar
request ondoes that request.

We must get and hold the "QMP" handle early, because we might get
back EPROBE_DEFER for that.  But the actual request should be sent
while we know the IPA clock is active, and when we know the
microcontroller is operational.

Fixes: 1aac309d3207 ("net: ipa: use autosuspend")
Signed-off-by: Alex Elder 
Signed-off-by: Jakub Kicinski 
Signed-off-by: Greg Kroah-Hartman

net: ipa: prevent concurrent replenish

2022-02-05T11:39:54+00:00

commit 998c0bd2b3715244da7639cc4e6a2062cb79c3f4 upstream.

We have seen cases where an endpoint RX completion interrupt arrives
while replenishing for the endpoint is underway.  This causes another
instance of replenishing to begin as part of completing the receive
transaction.  If this occurs it can lead to transaction corruption.

Use a new flag to ensure only one replenish instance for an endpoint
executes at a time.

Fixes: 84f9bd12d46db ("soc: qcom: ipa: IPA endpoints")
Signed-off-by: Alex Elder 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

net: ipa: use a bitmap for endpoint replenish_enabled

2022-02-05T11:39:54+00:00

commit c1aaa01dbf4cef95af3e04a5a43986c290e06ea3 upstream.

Define a new replenish_flags bitmap to contain Boolean flags
associated with an endpoint's replenishing state.  Replace the
replenish_enabled field with a flag in that bitmap.  This is to
prepare for the next patch, which adds another flag.

Signed-off-by: Alex Elder 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

net: ipa: fix atomic update in ipa_endpoint_replenish()

2022-01-27T11:03:01+00:00

commit 6c0e3b5ce94947b311348c367db9e11dcb2ccc93 upstream.

In ipa_endpoint_replenish(), if an error occurs when attempting to
replenish a receive buffer, we just quit and try again later.  In
that case we increment the backlog count to reflect that the attempt
was unsuccessful.  Then, if the add_one flag was true we increment
the backlog again.

This second increment is not included in the backlog local variable
though, and its value determines whether delayed work should be
scheduled.  This is a bug.

Fix this by determining whether 1 or 2 should be added to the
backlog before adding it in a atomic_add_return() call.

Reviewed-by: Matthias Kaehlcke 
Fixes: 84f9bd12d46db ("soc: qcom: ipa: IPA endpoints")
Signed-off-by: Alex Elder 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

net: ipa: kill ipa_cmd_pipeline_clear()

2021-11-23T12:26:40+00:00

Calling ipa_cmd_pipeline_clear() after stopping the channel
underlying the AP<-modem RX endpoint can lead to a deadlock.

This occurs in the ->runtime_suspend device power operation for the
IPA driver.  While this callback is in progress, any other requests
for power will block until the callback returns.

Stopping the AP<-modem RX channel does not prevent the modem from
sending another packet to this endpoint.  If a packet arrives for an
RX channel when the channel is stopped, an SUSPEND IPA interrupt
condition will be pending.  Handling an IPA interrupt requires
power, so ipa_isr_thread() calls pm_runtime_get_sync() first thing.

The problem occurs because a "pipeline clear" command will not
complete while such a SUSPEND interrupt condition exists.  So the
SUSPEND IPA interrupt handler won't proceed until it gets power;
that won't happen until the ->runtime_suspend callback (and its
"pipeline clear" command) completes; and that can't happen while
the SUSPEND interrupt condition exists.

It turns out that in this case there is no need to use the "pipeline
clear" command.  There are scenarios in which clearing the pipeline
is required while suspending, but those are not (yet) supported
upstream.  So a simple fix, avoiding the potential deadlock, is to
stop calling ipa_cmd_pipeline_clear() in ipa_endpoint_suspend().
This removes the only user of ipa_cmd_pipeline_clear(), so get rid
of that function.  It can be restored again whenever it's needed.

This is basically a manual revert along with an explanation for
commit 6cb63ea6a39ea ("net: ipa: introduce ipa_cmd_tag_process()").

Fixes: 6cb63ea6a39ea ("net: ipa: introduce ipa_cmd_tag_process()")
Signed-off-by: Alex Elder 
Signed-off-by: David S. Miller

net: ipa: separate disabling setup from modem stop

2021-11-23T12:06:40+00:00

The IPA setup_complete flag is set at the end of ipa_setup(), when
the setup phase of initialization has completed successfully.  This
occurs as part of driver probe processing, or (if "modem-init" is
specified in the DTS file) it is triggered by the "ipa-setup-ready"
SMP2P interrupt generated by the modem.

In the latter case, it's possible for driver shutdown (or remove) to
begin while setup processing is underway, and this can't be allowed.
The problem is that the setup_complete flag is not adequate to signal
that setup is underway.

If setup_complete is set, it will never be un-set, so that case is
not a problem.  But if setup_complete is false, there's a chance
setup is underway.

Because setup is triggered by an interrupt on a "modem-init" system,
there is a simple way to ensure the value of setup_complete is safe
to read.  The threaded handler--if it is executing--will complete as
part of a request to disable the "ipa-modem-ready" interrupt.  This
means that ipa_setup() (which is called from the handler) will run
to completion if it was underway, or will never be called otherwise.

The request to disable the "ipa-setup-ready" interrupt is currently
made within ipa_modem_stop().  Instead, disable the interrupt
outside that function in the two places it's called.  In the case of
ipa_remove(), this ensures the setup_complete flag is safe to read
before we read it.

Rename ipa_smp2p_disable() to be ipa_smp2p_irq_disable_setup(), to be
more specific about its effect.

Fixes: 530f9216a953 ("soc: qcom: ipa: AP/modem communications")
Signed-off-by: Alex Elder 
Signed-off-by: David S. Miller

net: ipa: directly disable ipa-setup-ready interrupt

2021-11-23T12:06:40+00:00

We currently maintain a "disabled" Boolean flag to determine whether
the "ipa-setup-ready" SMP2P IRQ handler does anything.  That flag
must be accessed under protection of a mutex.

Instead, disable the SMP2P interrupt when requested, which prevents
the interrupt handler from ever being called.  More importantly, it
synchronizes a thread disabling the interrupt with the completion of
the interrupt handler in case they run concurrently.

Use the IPA setup_complete flag rather than the disabled flag in the
handler to determine whether to ignore any interrupts arriving after
the first.

Rename the "disabled" flag to be "setup_disabled", to be specific
about its purpose.

Fixes: 530f9216a953 ("soc: qcom: ipa: AP/modem communications")
Signed-off-by: Alex Elder 
Signed-off-by: David S. Miller

net: ipa: disable HOLB drop when updating timer

2021-11-15T13:25:45+00:00

The head-of-line blocking timer should only be modified when
head-of-line drop is disabled.

One of the steps in recovering from a modem crash is to enable
dropping of packets with timeout of 0 (immediate).  We don't know
how the modem configured its endpoints, so before we program the
timer, we need to ensure HOL_BLOCK is disabled.

Fixes: 84f9bd12d46db ("soc: qcom: ipa: IPA endpoints")
Signed-off-by: Alex Elder 
Signed-off-by: David S. Miller