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  1. 22 Dec, 2016 6 commits
    • Sergei Miroshnichenko's avatar
      can: dev: fix deadlock reported after bus-off · d427d645
      Sergei Miroshnichenko authored 
      [ Upstream commit 9abefcb1 ]

A timer was used to restart after the bus-off state, leading to a
relatively large can_restart() executed in an interrupt context,
which in turn sets up pinctrl. When this happens during system boot,
there is a high probability of grabbing the pinctrl_list_mutex,
which is locked already by the probe() of other device, making the
kernel suspect a deadlock condition [1].

To resolve this issue, the restart_timer is replaced by a delayed
work.

[1] https://github.com/victronenergy/venus/issues/24Signed-off-by: default avatarSergei Miroshnichenko <sergeimir@emcraft.com>
Cc: linux-stable <stable@vger.kernel.org>
Signed-off-by: default avatarMarc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: default avatarSasha Levin <alexander.levin@verizon.com>
      d427d645
    • Joonwoo Park's avatar
      cpuset: handle race between CPU hotplug and cpuset_hotplug_work · 791a9289
      Joonwoo Park authored 
      [ Upstream commit 28b89b9e ]

A discrepancy between cpu_online_mask and cpuset's effective_cpus
mask is inevitable during hotplug since cpuset defers updating of
effective_cpus mask using a workqueue, during which time nothing
prevents the system from more hotplug operations.  For that reason
guarantee_online_cpus() walks up the cpuset hierarchy until it finds
an intersection under the assumption that top cpuset's effective_cpus
mask intersects with cpu_online_mask even with such a race occurring.

However a sequence of CPU hotplugs can open a time window, during which
none of the effective CPUs in the top cpuset intersect with
cpu_online_mask.

For example when there are 4 possible CPUs 0-3 and only CPU0 is online:

  ========================  ===========================
   cpu_online_mask           top_cpuset.effective_cpus
  ========================  ===========================
   echo 1 > cpu2/online.
   CPU hotplug notifier woke up hotplug work but not yet scheduled.
      [0,2]                     [0]

   echo 0 > cpu0/online.
   The workqueue is still runnable.
      [2]                       [0]
  ========================  ===========================

  Now there is no intersection between cpu_online_mask and
  top_cpuset.effective_cpus.  Thus invoking sys_sched_setaffinity() at
  this moment can cause following:

   Unable to handle kernel NULL pointer dereference at virtual address 000000d0
   ------------[ cut here ]------------
   Kernel BUG at ffffffc0001389b0 [verbose debug info unavailable]
   Internal error: Oops - BUG: 96000005 [#1] PREEMPT SMP
   Modules linked in:
   CPU: 2 PID: 1420 Comm: taskset Tainted: G        W       4.4.8+ #98
   task: ffffffc06a5c4880 ti: ffffffc06e124000 task.ti: ffffffc06e124000
   PC is at guarantee_online_cpus+0x2c/0x58
   LR is at cpuset_cpus_allowed+0x4c/0x6c
   <snip>
   Process taskset (pid: 1420, stack limit = 0xffffffc06e124020)
   Call trace:
   [<ffffffc0001389b0>] guarantee_online_cpus+0x2c/0x58
   [<ffffffc00013b208>] cpuset_cpus_allowed+0x4c/0x6c
   [<ffffffc0000d61f0>] sched_setaffinity+0xc0/0x1ac
   [<ffffffc0000d6374>] SyS_sched_setaffinity+0x98/0xac
   [<ffffffc000085cb0>] el0_svc_naked+0x24/0x28

The top cpuset's effective_cpus are guaranteed to be identical to
cpu_online_mask eventually.  Hence fall back to cpu_online_mask when
there is no intersection between top cpuset's effective_cpus and
cpu_online_mask.
Signed-off-by: default avatarJoonwoo Park <joonwoop@codeaurora.org>
Acked-by: default avatarLi Zefan <lizefan@huawei.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: cgroups@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: <stable@vger.kernel.org> # 3.17+
Signed-off-by: default avatarTejun Heo <tj@kernel.org>
Signed-off-by: default avatarSasha Levin <alexander.levin@verizon.com>
      791a9289
    • Karl Beldan's avatar
      mtd: nand: davinci: Reinitialize the HW ECC engine in 4bit hwctl · 6b82b060
      Karl Beldan authored 
      [ Upstream commit f6d7c1b5 ]

This fixes subpage writes when using 4-bit HW ECC.

There has been numerous reports about ECC errors with devices using this
driver for a while.  Also the 4-bit ECC has been reported as broken with
subpages in [1] and with 16 bits NANDs in the driver and in mach* board
files both in mainline and in the vendor BSPs.

What I saw with 4-bit ECC on a 16bits NAND (on an LCDK) which got me to
try reinitializing the ECC engine:
- R/W on whole pages properly generates/checks RS code
- try writing the 1st subpage only of a blank page, the subpage is well
  written and the RS code properly generated, re-reading the same page
  the HW detects some ECC error, reading the same page again no ECC
  error is detected

Note that the ECC engine is already reinitialized in the 1-bit case.

Tested on my LCDK with UBI+UBIFS using subpages.
This could potentially get rid of the issue workarounded in [1].

[1] 28c015a9 ("mtd: davinci-nand: disable subpage write for keystone-nand")

Fixes: 6a4123e5 ("mtd: nand: davinci_nand, 4-bit ECC for smallpage")
Cc: <stable@vger.kernel.org>
Signed-off-by: default avatarKarl Beldan <kbeldan@baylibre.com>
Acked-by: default avatarBoris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: default avatarBrian Norris <computersforpeace@gmail.com>
Signed-off-by: default avatarSasha Levin <alexander.levin@verizon.com>
      6b82b060
    • Rob Clark's avatar
      drm/msm: fix use of copy_from_user() while holding spinlock · e537a097
      Rob Clark authored 
      [ Upstream commit 89f82cbb ]

Use instead __copy_from_user_inatomic() and fallback to slow-path where
we drop and re-aquire the lock in case of fault.

Cc: stable@vger.kernel.org
Reported-by: default avatarVaishali Thakkar <vaishali.thakkar@oracle.com>
Signed-off-by: default avatarRob Clark <robdclark@gmail.com>
Signed-off-by: default avatarSasha Levin <alexander.levin@verizon.com>
      e537a097
    • Pawel Moll's avatar
      bus: arm-ccn: Fix PMU handling of MN · b56eb9cd
      Pawel Moll authored 
      [ Upstream commit 4e486cba ]

The "Miscellaneous Node" fell through cracks of node initialisation,
as its ID is shared with HN-I.

This patch treats MN as a special case (which it is), adding separate
validation check for it and pre-defining the node ID in relevant events
descriptions. That way one can simply run:

	# perf stat -a -e ccn/mn_ecbarrier/ <workload>

Additionally, direction in the MN pseudo-events XP watchpoint
definitions is corrected to be "TX" (1) as they are defined from the
crosspoint point of view (thus barriers are transmitted from XP to MN).

Cc: stable@vger.kernel.org # 3.17+
Signed-off-by: default avatarPawel Moll <pawel.moll@arm.com>
Signed-off-by: default avatarSasha Levin <alexander.levin@verizon.com>
      b56eb9cd
    • Pawel Moll's avatar
      bus: arm-ccn: Provide required event arguments · 7298a8bf
      Pawel Moll authored 
      [ Upstream commit 8f06c51f ]

Since 688d4dfc "perf tools: Support
parsing parameterized events" the perf userspace tools understands
"argument=?" syntax in the events file, making sure that required
arguments are provided by the user and not defaulting to 0, causing
confusion.

This patch adds the required arguments lists for CCN events.
Signed-off-by: default avatarPawel Moll <pawel.moll@arm.com>
Signed-off-by: default avatarSasha Levin <alexander.levin@verizon.com>
      7298a8bf
  3. 29 Nov, 2016 1 commit
  5. 26 Nov, 2016 28 commits
  7. 24 Nov, 2016 5 commits
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