Skip to content

R
raspberrypi-kernel

openeuler / raspberrypi-kernel

通知 13
Star 1
Fork 0
R
raspberrypi-kernel
切换分支/标签
  1. 27 2月, 2016 3 次提交
  3. 23 2月, 2016 1 次提交
    • V
      intel_pstate: Update frequencies of policy->cpus only from ->set_policy() · 41cfd64c
      由 Viresh Kumar 提交于 
      The intel-pstate driver is using intel_pstate_hwp_set() from two
separate paths, i.e. ->set_policy() callback and sysfs update path for
the files present in /sys/devices/system/cpu/intel_pstate/ directory.

While an update to the sysfs path applies to all the CPUs being managed
by the driver (which essentially means all the online CPUs), the update
via the ->set_policy() callback applies to a smaller group of CPUs
managed by the policy for which ->set_policy() is called.

And so, intel_pstate_hwp_set() should update frequencies of only the
CPUs that are part of policy->cpus mask, while it is called from
->set_policy() callback.

In order to do that, add a parameter (cpumask) to intel_pstate_hwp_set()
and apply the frequency changes only to the concerned CPUs.

For ->set_policy() path, we are only concerned about policy->cpus, and
so policy->rwsem lock taken by the core prior to calling ->set_policy()
is enough to take care of any races. The larger lock acquired by
get_online_cpus() is required only for the updates to sysfs files.

Add another routine, intel_pstate_hwp_set_online_cpus(), and call it
from the sysfs update paths.

This also fixes a lockdep reported recently, where policy->rwsem and
get_online_cpus() could have been acquired in any order causing an ABBA
deadlock. The sequence of events leading to that was:

intel_pstate_init(...)
	...cpufreq_online(...)
		down_write(&policy->rwsem); // Locks policy->rwsem
		...
		cpufreq_init_policy(policy);
			...intel_pstate_hwp_set();
				get_online_cpus(); // Temporarily locks cpu_hotplug.lock
		...
		up_write(&policy->rwsem);

pm_suspend(...)
	...disable_nonboot_cpus()
		_cpu_down()
			cpu_hotplug_begin(); // Locks cpu_hotplug.lock
			__cpu_notify(CPU_DOWN_PREPARE, ...);
				...cpufreq_offline_prepare();
					down_write(&policy->rwsem); // Locks policy->rwsem
Reported-and-tested-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Acked-by: NSrinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
      41cfd64c
  5. 22 2月, 2016 2 次提交
  7. 13 2月, 2016 1 次提交
  9. 11 2月, 2016 9 次提交
  11. 10 2月, 2016 7 次提交
  13. 05 2月, 2016 15 次提交
  15. 04 2月, 2016 2 次提交
    • M
      [media] vb2-core: call threadio->fnc() if !VB2_BUF_STATE_ERROR · 1f2c4501
      由 Mauro Carvalho Chehab 提交于 
      changeset 70433a15 ("media: videobuf2: Refactor vb2_fileio_data
and vb2_thread") broke videobuf2-dvb.

The root cause is that, instead of calling threadio->fnc() for
all types of events except for VB2_BUF_STATE_ERROR, it was calling
it only for VB2_BUF_STATE_DONE.

With that, the DVB thread were never called.

Cc: stable@vger.kernel.org # Kernel >= 4.3
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>
      1f2c4501
    • H
      [media] vb2: fix nasty vb2_thread regression · fac710e4
      由 Hans Verkuil 提交于 
      The vb2_thread implementation was made generic and was moved from
videobuf2-v4l2.c to videobuf2-core.c in commit af3bac1a. Unfortunately
that clearly was never tested since it broke read() causing NULL address
references.

The root cause was confused handling of vb2_buffer vs v4l2_buffer (the pb
pointer in various core functions).

The v4l2_buffer no longer exists after moving the code into the core and
it is no longer needed. However, the vb2_thread code passed a pointer to
a vb2_buffer to the core functions were a v4l2_buffer pointer was expected
and vb2_thread expected that the vb2_buffer fields would be filled in
correctly.

This is obviously wrong since v4l2_buffer != vb2_buffer. Note that the
pb pointer is a void pointer, so no type-checking took place.

This patch fixes this problem:

1) allow pb to be NULL for vb2_core_(d)qbuf. The vb2_thread code will use
   a NULL pointer here since they don't care about v4l2_buffer anyway.
2) let vb2_core_dqbuf pass back the index of the received buffer. This is
   all vb2_thread needs: this index is the index into the q->bufs array
   and vb2_thread just gets the vb2_buffer from there.
3) the fileio->b pointer (that originally contained a v4l2_buffer) is
   removed altogether since it is no longer needed.

Tested with vivid and the cobalt driver.

Cc: stable@vger.kernel.org # Kernel >= 4.3
Signed-off-by: NHans Verkuil <hans.verkuil@cisco.com>
Reported-by: NMatthias Schwarzott <zzam@gentoo.org>
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>
      fac710e4