linux-stable.git/drivers/usb/early, branch v4.12 Linux kernel stable tree usb/early: Add driver for xhci debug capability 2017-03-21T11:30:05+00:00 Lu Baolu baolu.lu@linux.intel.com 2017-03-21T08:01:30+00:00 aeb9dd1de98c1a5f2007ea5d2a154c1244caf8a0 XHCI debug capability (DbC) is an optional but standalone functionality provided by an xHCI host controller. Software learns this capability by walking through the extended capability list of the host. XHCI specification describes DbC in section 7.6. This patch introduces the code to probe and initialize the debug capability hardware during early boot. With hardware initialized, the debug target (system on which this code is running) will present a debug device through the debug port (normally the first USB3 port). The debug device is fully compliant with the USB framework and provides the equivalent of a very high performance (USB3) full-duplex serial link between the debug host and target. The DbC functionality is independent of the xHCI host. There isn't any precondition from the xHCI host side for the DbC to work. One use for this feature is kernel debugging, for example when your machine crashes very early before the regular console code is initialized. Other uses include simpler, lockless logging instead of a full-blown printk console driver and klogd. Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com> Acked-by: Thomas Gleixner <tglx@linutronix.de> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mathias Nyman <mathias.nyman@linux.intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: linux-usb@vger.kernel.org Link: http://lkml.kernel.org/r/1490083293-3792-3-git-send-email-baolu.lu@linux.intel.com [ Small fix to the Kconfig help text. ] Signed-off-by: Ingo Molnar <mingo@kernel.org> 
XHCI debug capability (DbC) is an optional but standalone
functionality provided by an xHCI host controller. Software
learns this capability by walking through the extended
capability list of the host. XHCI specification describes
DbC in section 7.6.

This patch introduces the code to probe and initialize the
debug capability hardware during early boot. With hardware
initialized, the debug target (system on which this code is
running) will present a debug device through the debug port
(normally the first USB3 port). The debug device is fully
compliant with the USB framework and provides the equivalent
of a very high performance (USB3) full-duplex serial link
between the debug host and target. The DbC functionality is
independent of the xHCI host. There isn't any precondition
from the xHCI host side for the DbC to work.

One use for this feature is kernel debugging, for example
when your machine crashes very early before the regular
console code is initialized. Other uses include simpler,
lockless logging instead of a full-blown printk console
driver and klogd.

Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mathias Nyman <mathias.nyman@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: linux-usb@vger.kernel.org
Link: http://lkml.kernel.org/r/1490083293-3792-3-git-send-email-baolu.lu@linux.intel.com
[ Small fix to the Kconfig help text. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
drivers: usb: early: remove unused code 2017-02-08T06:43:47+00:00 Gustavo A. R. Silva garsilva@embeddedor.com 2017-02-08T06:18:50+00:00 3d95521c12d84d917d2f7ec3e002d4b0e0ef3c28 Remove this line of code because devnum is overwritten before it can be used. This could happen if line of code 609 (goto try_again;) is executed. Otherwise, devnum is never used again. Addresses-Coverity-ID: 1226870 Signed-off-by: Gustavo A. R. Silva <garsilva@embeddedor.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
Remove this line of code because devnum is overwritten before it can be used.
This could happen if line of code 609 (goto try_again;) is executed. Otherwise,
devnum is never used again.

Addresses-Coverity-ID: 1226870
Signed-off-by: Gustavo A. R. Silva <garsilva@embeddedor.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
treewide: remove redundant #include <linux/kconfig.h> 2016-10-11T22:06:33+00:00 Masahiro Yamada yamada.masahiro@socionext.com 2016-10-11T20:55:58+00:00 97139d4a6f26445de47b378cddd5192c0278f863 Kernel source files need not include <linux/kconfig.h> explicitly because the top Makefile forces to include it with: -include $(srctree)/include/linux/kconfig.h This commit removes explicit includes except the following: * arch/s390/include/asm/facilities_src.h * tools/testing/radix-tree/linux/kernel.h These two are used for host programs. Link: http://lkml.kernel.org/r/1473656164-11929-1-git-send-email-yamada.masahiro@socionext.com Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> 
Kernel source files need not include <linux/kconfig.h> explicitly
because the top Makefile forces to include it with:

  -include $(srctree)/include/linux/kconfig.h

This commit removes explicit includes except the following:

  * arch/s390/include/asm/facilities_src.h
  * tools/testing/radix-tree/linux/kernel.h

These two are used for host programs.

Link: http://lkml.kernel.org/r/1473656164-11929-1-git-send-email-yamada.masahiro@socionext.com
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
usb: early/ehci-dbgp: make it explicitly non-modular 2016-06-26T18:48:18+00:00 Paul Gortmaker paul.gortmaker@windriver.com 2016-06-15T21:52:14+00:00 4e84e22195910b315b36eca149febd0a6b02f7c4 The Kconfig currently controlling compilation of this code is: arch/x86/Kconfig.debug:config EARLY_PRINTK_DBGP arch/x86/Kconfig.debug: bool "Early printk via EHCI debug port" ...meaning that it currently is not being built as a module by anyone. Lets remove the couple traces of modularity so that when reading the driver there is no doubt it is builtin-only. Since module_init translates to device_initcall in the non-modular case, the init ordering remains unchanged with this commit. Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: linux-usb@vger.kernel.org Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
The Kconfig currently controlling compilation of this code is:

arch/x86/Kconfig.debug:config EARLY_PRINTK_DBGP
arch/x86/Kconfig.debug: bool "Early printk via EHCI debug port"

...meaning that it currently is not being built as a module by anyone.

Lets remove the couple traces of modularity so that when reading the
driver there is no doubt it is builtin-only.

Since module_init translates to device_initcall in the non-modular
case, the init ordering remains unchanged with this commit.

Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: linux-usb@vger.kernel.org
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
USB: ehci-dbgp: drop dead code. 2013-09-26T23:25:21+00:00 Tim Deegan tim@xen.org 2013-09-12T15:08:10+00:00 8c9247a6b5e57d04e55d94ecbfd9e9d61c2a01e1 We can only reach this spot by breaking out of the scan loop, so by construction ret > 0. Found by Coverity, in a copy of this file in the Xen sources. Signed-off-by: Tim Deegan <tim@xen.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
We can only reach this spot by breaking out of the scan loop,
so by construction ret > 0.

Found by Coverity, in a copy of this file in the Xen sources.

Signed-off-by: Tim Deegan <tim@xen.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
fix build of EHCI debug port code when USB_CHIPIDEA but !USB_EHCI_HCD 2012-11-02T17:13:33+00:00 Jan Beulich JBeulich@suse.com 2012-11-02T17:09:00+00:00 bc8d51ea7e8ae0abb90fa89407b55a7e0bcb0a2a Relax condition of building the reset interface stubs in drivers/usb/early/ehci-dbgp.c from USB_EHCI_HCD to just USB, to also cover the chipidea driver re-using code from ehci-hcd. Reported-by: Randy Dunlap <rdunlap@xenotime.net> Signed-off-by: Jan Beulich <jbeulich@suse.com> Acked-by: Alan Stern <stern@rowland.harvard.edu> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Stefano Stabellini <stefano.stabellini@eu.citrix.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
Relax condition of building the reset interface stubs in
drivers/usb/early/ehci-dbgp.c from USB_EHCI_HCD to just USB, to also
cover the chipidea driver re-using code from ehci-hcd.

Reported-by: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
USB: fix build with XEN and EARLY_PRINTK_DBGP enabled but USB_SUPPORT disabled 2012-10-30T20:19:30+00:00 Jan Beulich JBeulich@suse.com 2012-10-29T16:45:54+00:00 86effe5980e25f4fac10a0f22938c2fcd4a32690 Since there's no possible caller of dbgp_external_startup() and dbgp_reset_prep() when !USB_EHCI_HCD, there's no point in building and exporting these functions in that case. This eliminates a build error under the conditions listed in the subject, introduced with the merge f1c6872e4980bc4078cfaead05f892b3d78dea64. Reported-by: Randy Dunlap <rdunlap@xenotime.net> Signed-off-by: Jan Beulich <jbeulich@suse.com> Cc: Stefano Stabellini <stefano.stabellini@eu.citrix.com> Acked-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
Since there's no possible caller of dbgp_external_startup() and
dbgp_reset_prep() when !USB_EHCI_HCD, there's no point in building and
exporting these functions in that case. This eliminates a build error
under the conditions listed in the subject, introduced with the merge
f1c6872e4980bc4078cfaead05f892b3d78dea64.

Reported-by: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Cc: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
USB EHCI/Xen: propagate controller reset information to hypervisor 2012-09-18T16:20:48+00:00 Jan Beulich JBeulich@suse.com 2012-09-18T11:23:02+00:00 9fa5780beea1274d498a224822397100022da7d4 Just like for the in-tree early console debug port driver, the hypervisor - when using a debug port based console - also needs to be told about controller resets, so it can suppress using and then re-initialize the debug port accordingly. Other than the in-tree driver, the hypervisor driver actually cares about doing this only for the device where the debug is port actually in use, i.e. it needs to be told the coordinates of the device being reset (quite obviously, leveraging the addition done for that would likely benefit the in-tree driver too). Signed-off-by: Jan Beulich <jbeulich@suse.com> Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Acked-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
Just like for the in-tree early console debug port driver, the
hypervisor - when using a debug port based console - also needs to be
told about controller resets, so it can suppress using and then
re-initialize the debug port accordingly.

Other than the in-tree driver, the hypervisor driver actually cares
about doing this only for the device where the debug is port actually
in use, i.e. it needs to be told the coordinates of the device being
reset (quite obviously, leveraging the addition done for that would
likely benefit the in-tree driver too).

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Merge tag 'for_linux-3.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jwessel/kgdb 2012-08-03T17:53:47+00:00 Linus Torvalds torvalds@linux-foundation.org 2012-08-03T17:53:47+00:00 d97e1dcde5e19ed1f828baff4ab5fd0e517c8dae Pull KGDB/KDB/usb-dbgp fixes and cleanups from Jason Wessel: "There are no new features, those will be delayed to the 3.7 window. There are only fixes/cleanup against the usual kernel churn and we are removing more lines than we add: - usb-dbgp - increase the controller wait time to come out of halt. - kdb - Remove unused KDB_FLAG_ONLY_DO_DUMP code and cpu in more prompt - debug core - pass NMI type on archs that provide NMI types" * tag 'for_linux-3.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jwessel/kgdb: USB: echi-dbgp: increase the controller wait time to come out of halt. kernel/debug: Make use of KGDB_REASON_NMI kdb: Remove cpu from the more prompt kdb: Remove unused KDB_FLAG_ONLY_DO_DUMP 
Pull KGDB/KDB/usb-dbgp fixes and cleanups from Jason Wessel:
 "There are no new features, those will be delayed to the 3.7 window.
  There are only fixes/cleanup against the usual kernel churn and we are
  removing more lines than we add:

   - usb-dbgp - increase the controller wait time to come out of halt.
   - kdb - Remove unused KDB_FLAG_ONLY_DO_DUMP code and cpu in more prompt
   - debug core - pass NMI type on archs that provide NMI types"

* tag 'for_linux-3.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jwessel/kgdb:
  USB: echi-dbgp: increase the controller wait time to come out of halt.
  kernel/debug: Make use of KGDB_REASON_NMI
  kdb: Remove cpu from the more prompt
  kdb: Remove unused KDB_FLAG_ONLY_DO_DUMP
USB: echi-dbgp: increase the controller wait time to come out of halt. 2012-07-31T13:16:43+00:00 Colin Ian King colin.king@canonical.com 2012-07-30T15:06:42+00:00 f96a4216e85050c0a9d41a41ecb0ae9d8e39b509 The default 10 microsecond delay for the controller to come out of halt in dbgp_ehci_startup is too short, so increase it to 1 millisecond. This is based on emperical testing on various USB debug ports on modern machines such as a Lenovo X220i and an Ivybridge development platform that needed to wait ~450-950 microseconds. Cc: <stable@vger.kernel.org> Signed-off-by: Colin Ian King <colin.king@canonical.com> Signed-off-by: Jason Wessel <jason.wessel@windriver.com> 
The default 10 microsecond delay for the controller to come out of
halt in dbgp_ehci_startup is too short, so increase it to 1 millisecond.

This is based on emperical testing on various USB debug ports on
modern machines such as a Lenovo X220i and an Ivybridge development
platform that needed to wait ~450-950 microseconds.

Cc: <stable@vger.kernel.org>
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>