提交 · eba92811f5c7ad9fadf40f021c1b85ad0de3bcc4 · openanolis / cloud-kernel

This is the first step of renaming async commit to nonblocking commit.
The flag passed by userspace is NONBLOCKING, and async has a different
meaning for page flips, where it means as soon as possible.

Fixing up comments in drm core is done manually, to make sure I didn't
miss anything.

For drivers, the following cocci script is used to rename bool async to bool
nonblock:
@@
identifier I =~ "^async";
identifier func;
@@
func(..., bool
- I
+ nonblock
, ...)
{
<...
- I
+ nonblock
...>
}
@@
identifier func;
type T;
identifier I =~ "^async";
@@
T func(..., bool
- I
+ nonblock
, ...);

Thanks to Tvrtko Ursulin for the cocci script.

Cc: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>
Signed-off-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1461679905-30177-2-git-send-email-maarten.lankhorst@linux.intel.com

286dbb8d

drm/udl: Use drm_fb_helper deferred_io support · e3758824

由 Noralf Trønnes 提交于 4月 28, 2016

Use the fbdev deferred io support in drm_fb_helper.
The (struct fb_ops *)->fb_{fillrect,copyarea,imageblit} functions will
now schedule a worker instead of being flushed directly like it was
previously (recorded when in atomic).

This patch has only been compile tested.
Signed-off-by: NNoralf Trønnes <noralf@tronnes.org>
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Tested-by: NGerd Hoffmann <kraxel@redhat.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1461856717-6476-8-git-send-email-noralf@tronnes.org

e3758824

drm/qxl: Use drm_fb_helper deferred_io support · 6819c3c2

由 Noralf Trønnes 提交于 4月 28, 2016

Use the fbdev deferred io support in drm_fb_helper which mirrors the
one qxl has had.
This patch has only been compile tested.
Signed-off-by: NNoralf Trønnes <noralf@tronnes.org>
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Tested-by: NGerd Hoffmann <kraxel@redhat.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1461856717-6476-7-git-send-email-noralf@tronnes.org

6819c3c2

drm/fb-cma-helper: Add fb_deferred_io support · 199c7717

由 Noralf Trønnes 提交于 4月 28, 2016

This adds fbdev deferred io support if CONFIG_FB_DEFERRED_IO is enabled.
The driver has to provide a (struct drm_framebuffer_funcs *)->dirty()
callback to get notification of fbdev framebuffer changes.
If the dirty() hook is set, then fb_deferred_io is set up automatically
by the helper.

Two functions have been added so that the driver can provide a dirty()
function:
- drm_fbdev_cma_init_with_funcs()
  This makes it possible for the driver to provided a custom
  (struct drm_fb_helper_funcs *)->fb_probe() function.
- drm_fbdev_cma_create_with_funcs()
  This is used by the .fb_probe hook to set a driver provided
  (struct drm_framebuffer_funcs *)->dirty() function.

Cc: laurent.pinchart@ideasonboard.com
Signed-off-by: NNoralf Trønnes <noralf@tronnes.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1461856717-6476-6-git-send-email-noralf@tronnes.org

199c7717

fbdev: fb_defio: Export fb_deferred_io_mmap · ba026334

由 Noralf Trønnes 提交于 4月 28, 2016

Export fb_deferred_io_mmap so drivers can change vma->vm_page_prot.
When the framebuffer memory is allocated using dma_alloc_writecombine()
instead of vmalloc(), I get cache syncing problems on ARM.
This solves it:

static int drm_fbdev_cma_deferred_io_mmap(struct fb_info *info,
					  struct vm_area_struct *vma)
{
	fb_deferred_io_mmap(info, vma);
	vma->vm_page_prot = pgprot_writecombine(vma->vm_page_prot);

	return 0;
}

Could this have been done in the core?
Drivers that don't set (struct fb_ops *)->fb_mmap, gets a call to
fb_pgprotect() at the end of the default fb_mmap implementation
(drivers/video/fbdev/core/fbmem.c). This is an architecture specific
function that on many platforms uses pgprot_writecombine(), but not on
all. And looking at some of the fb_mmap implementations, some of them
sets vm_page_prot to nocache for instance, so I think the safest bet is
to do this in the driver and not in the fbdev core. And we can't call
fb_pgprotect() from fb_deferred_io_mmap() either because we don't have
access to the file pointer that powerpc needs.
Signed-off-by: NNoralf Trønnes <noralf@tronnes.org>
Acked-by: NTomi Valkeinen <tomi.valkeinen@ti.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1461856717-6476-5-git-send-email-noralf@tronnes.org

ba026334

drm/fb-helper: Add fb_deferred_io support · eaa434de

由 Noralf Trønnes 提交于 4月 28, 2016

This adds deferred io support to drm_fb_helper.
The fbdev framebuffer changes are flushed using the callback
(struct drm_framebuffer *)->funcs->dirty() by a dedicated worker
ensuring that it always runs in process context.

For those wondering why we need to be able to handle atomic calling
contexts: Both panic paths and cursor code and fbcon blanking can run
from atomic. See

commit bcb39af4
Author: Dave Airlie <airlied@redhat.com>
Date:   Thu Feb 7 11:19:15 2013 +1000

    drm/udl: make usage as a console safer

for where this was originally discovered.
Signed-off-by: NNoralf Trønnes <noralf@tronnes.org>
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
[danvet: Augment commit message with why we need to handle atomic
contexts.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1461856717-6476-4-git-send-email-noralf@tronnes.org

eaa434de

drm/qxl: Change drm_fb_helper_sys_*() calls to sys_*() · 2b5e8e57

由 Noralf Trønnes 提交于 4月 28, 2016

Now that drm_fb_helper gets deferred io support, the
drm_fb_helper_sys_{fillrect,copyarea,imageblit} functions will schedule
a worker that will call the (struct drm_framebuffer *)->funcs->dirty()
function. This will break this driver so use the
sys_{fillrect,copyarea,imageblit} functions directly.
Signed-off-by: NNoralf Trønnes <noralf@tronnes.org>
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1461856717-6476-3-git-send-email-noralf@tronnes.org

2b5e8e57

drm/udl: Change drm_fb_helper_sys_*() calls to sys_*() · 302f0e26

由 Noralf Trønnes 提交于 4月 28, 2016

302f0e26

28 4月, 2016 4 次提交

drm/atomic: Add missing drm_crtc_internal.h include · be35f94f

由 Thierry Reding 提交于 4月 28, 2016

Some of the functions implemented are flagged as not having a prototype
defined when building with W=1. Include the header to avoid these build
warnings.
Signed-off-by: NThierry Reding <treding@nvidia.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1461849596-12819-1-git-send-email-thierry.reding@gmail.com

be35f94f

drm/dp: Allow signals to interrupt drm_aux-dev reads/writes · 36230cb5

由 Ville Syrjälä 提交于 4月 27, 2016

Let's be nice and interrupt the dpcd aux-dev reads/writes when there's
a signal pending. Much nicer if the user can hit ^C instead of having to
sit around waiting for the read/write to finish.

time dd if=/dev/drm_dp_aux0 bs=$((1024*1024))
^C

before:
 real	0m34.681s
 user	0m0.003s
 sys	0m6.880s

after:
 real	0m0.222s
 user	0m0.006s
 sys	0m0.057s

Cc: Rafael Antognolli <rafael.antognolli@intel.com>
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NJani Nikula <jani.nikula@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1461786225-7790-1-git-send-email-ville.syrjala@linux.intel.com

36230cb5

drm: Quiet down drm_mode_getresources · 676fb324

由 Tvrtko Ursulin 提交于 4月 27, 2016

The debug logging here can be very verbose in the kernel logs
and provides no information which userspace doesn't have the
access to already. Turn it off so kernel logs become more
manageable.
Signed-off-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: dri-devel@lists.freedesktop.org
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1461755507-30453-1-git-send-email-tvrtko.ursulin@linux.intel.com

676fb324

drm: Quiet down drm_mode_getconnector · 3849bef3

由 Tvrtko Ursulin 提交于 4月 27, 2016

Debug logging in this function does not provide any information
apart that the userspace is calling an ioctl on the connector.

There is not any info on the connector provided at all and
since there are other ioctls userspace typically calls which
do log useful things about the same connectors, remove this
one to make things a little bit more readable when KMS debugging
is turned on.
Signed-off-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: dri-devel@lists.freedesktop.org
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1461751622-26927-10-git-send-email-tvrtko.ursulin@linux.intel.com

3849bef3

27 4月, 2016 8 次提交

drm: Protect dev->filelist with its own mutex · 1d2ac403

由 Daniel Vetter 提交于 4月 26, 2016

amdgpu gained dev->struct_mutex usage, and that's because it's walking
the dev->filelist list. Protect that list with it's own lock to take
one more step towards getting rid of struct_mutex usage in drivers
once and for all.

While doing the conversion I noticed that 2 debugfs files in i915
completely lacked appropriate locking. Fix that up too.

v2: don't forget to switch to drm_gem_object_unreference_unlocked.

Cc: Alex Deucher <alexander.deucher@amd.com>
Reviewed-by: NAlex Deucher <alexander.deucher@amd.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1461691808-12414-9-git-send-email-daniel.vetter@ffwll.ch

1d2ac403

drm: Make drm_vm_open/close_locked private to drm_vm.c · f47dbdd7

由 Daniel Vetter 提交于 4月 26, 2016

It's only used for legacy mmaping support now.
Reviewed-by: NAlex Deucher <alexander.deucher@amd.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1461691808-12414-8-git-send-email-daniel.vetter@ffwll.ch

f47dbdd7

drm: Hide master MAP cleanup in drm_bufs.c · 40647e45

由 Daniel Vetter 提交于 4月 27, 2016

And again make sure it's a no-op for modern drivers. Another case of
dev->struct_mutex gone for modern drivers!

Note that the entirety of the legacy addmap interface is now protected
by DRIVER_MODESET. Note that just auditing kernel code is not enough,
since userspace loves to set up legacy maps on it's own for various
things - with ums userspace and kernel space share control over
resources.

v2: Also add a DRIVER_* check like for all other maps functions to
really short-circuit the code. And give drm_legacy_rmmap used by the
dev unregister code the same treatment.

v3:
- remove redundant return; (Alex, Chris)
- don't special case nouveau with DRIVER_KMS_LEGACY_CONTEXT.

v4: Again special case nouveau. The problem is not directly in the
ddx, but that it calls dri1 functions from the X server. And those do
call drmAddMap. Fixed only in

    commit b1a630b48210d6a3c44994fce1b73273000ace5c
    Author: Dave Airlie <airlied@redhat.com>
    Date:   Wed Nov 7 14:45:14 2012 +1000

        nouveau: drop DRI1 device open interface.
Acked-by: NAlex Deucher <alexander.deucher@amd.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1461741618-12679-1-git-send-email-daniel.vetter@ffwll.ch

40647e45

drm: Forbid legacy MAP functions for DRIVER_MODESET · e975eef0

由 Daniel Vetter 提交于 4月 26, 2016

Like in

commit 0e975980
Author: Peter Antoine <peter.antoine@intel.com>
Date:   Tue Jun 23 08:18:49 2015 +0100

    drm: Turn off Legacy Context Functions

we need to again make an exception for nouveau, but everyone else
really doesn't need this.

Dave Airlie dug out again why we need this: The problem is the legacy
dri1 open function the nouveau ddx called, and the problematic code is
actually in the X server itself. It was only fixed in

commit b1a630b48210d6a3c44994fce1b73273000ace5c
Author: Dave Airlie <airlied@redhat.com>
Date:   Wed Nov 7 14:45:14 2012 +1000

    nouveau: drop DRI1 device open interface.

Cc: Peter Antoine <peter.antoine@intel.com>
Cc: Ben Skeggs <bskeggs@redhat.com>
Acked-by: NAlex Deucher <alexander.deucher@amd.com>
Acked-by: NDave Airlie <airlied@redhat.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1461691808-12414-5-git-send-email-daniel.vetter@ffwll.ch
Link: http://patchwork.freedesktop.org/patch/msgid/1461691808-12414-6-git-send-email-daniel.vetter@ffwll.ch

e975eef0

drm: Push struct_mutex into ->master_destroy · 0d787b14

由 Daniel Vetter 提交于 4月 26, 2016

Only two drivers implement this hook. vmwgfx (which doesn't need it
really) and legacy radeon (which since v1 has been nuked, yay).

v1: Rebase over radeon ums removal.

Cc: Thomas Hellstrom <thellstrom@vmware.com>
Cc: Alex Deucher <alexdeucher@gmail.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NAlex Deucher <alexander.deucher@amd.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1461691808-12414-6-git-send-email-daniel.vetter@ffwll.ch

0d787b14

drm: Move drm_getmap into drm_bufs.c and give it a legacy prefix · ec1f52ef

由 Daniel Vetter 提交于 4月 26, 2016

It belongs right next to the addmap and rmmap functions really. And
for OCD consistency name it drm_legacy_getmap_ioctl.
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NAlex Deucher <alexander.deucher@amd.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1461691808-12414-4-git-send-email-daniel.vetter@ffwll.ch

ec1f52ef

drm: Put legacy lastclose work into drm_legacy_dev_reinit · 68dfbeba

由 Daniel Vetter 提交于 4月 26, 2016

Except for the ->lasclose driver callback evrything in drm_lastclose()
is all legacy cruft and can be hidden. Which means another
dev->struct_mutex site disappears entirely for modern drivers!

Also while at it change the return value of drm_lastclose to void
since it will always succeed. No one checks the return value of
close() anyway, ever.

v2: Move misplaced hunk, spotted by 0day.

Cc: Thierry Reding <thierry.reding@gmail.com>
Reviewed-by: NAlex Deucher <alexander.deucher@amd.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1461691808-12414-3-git-send-email-daniel.vetter@ffwll.ch

68dfbeba

drm: Give drm_agp_clear drm_legacy_ prefix · 366884b1

由 Daniel Vetter 提交于 4月 26, 2016

It has a  DRIVER_MODESET check to sure make it's not creating havoc
for drm drivers. Make that clear in the name too.

v2: Move misplaced hunk, spotted by 0day and Thierry.

Cc: Thierry Reding <thierry.reding@gmail.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Acked-by: NAlex Deucher <alexander.deucher@amd.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1461691808-12414-2-git-send-email-daniel.vetter@ffwll.ch

366884b1

26 4月, 2016 1 次提交

drm/sysfs: Annote lockless show functions with READ_ONCE · 4eb9b945

由 Daniel Vetter 提交于 3月 30, 2016

For documentation and paranoia.
Acked-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1459331120-27864-4-git-send-email-daniel.vetter@ffwll.ch

4eb9b945

25 4月, 2016 1 次提交

MAINTAINERS: Update the files list for the GMA500 DRM driver · 5ff18e42

由 Emil Velikov 提交于 4月 22, 2016

Cc: Patrik Jakobsson <patrik.r.jakobsson@gmail.com>
Cc: dri-devel@lists.freedesktop.org
Signed-off-by: NEmil Velikov <emil.l.velikov@gmail.com>
Acked-by: NPatrik Jakobsson <patrik.r.jakobsson@gmail.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1461279842-28695-5-git-send-email-emil.l.velikov@gmail.com

5ff18e42

23 4月, 2016 5 次提交

drm: rcar-du: Fix compilation warning · c251d85d

由 Laurent Pinchart 提交于 4月 22, 2016

Commit d63c25e4 ("drm: rcar-du: Use generic
drm_connector_register_all() helper") left an unused local variable
behind. Remove it.

Fixes: d63c25e4 ("drm: rcar-du: Use generic drm_connector_register_all() helper")
Signed-off-by: NLaurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1461336879-2469-1-git-send-email-laurent.pinchart+renesas@ideasonboard.com

c251d85d

drm/i915: Get rid of intel_dp_dpcd_read_wake() · 9f085ebb

由 Lyude 提交于 4月 13, 2016

Since we've fixed up drm_dp_dpcd_read() to allow for retries when things
timeout, there's no use for having this function anymore. Good riddens.
Signed-off-by: NLyude <cpaul@redhat.com>
Tested-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1460559513-32280-5-git-send-email-cpaul@redhat.com

9f085ebb

drm/dp_helper: Perform throw-away read before actual read in drm_dp_dpcd_read() · f808f633

由 Lyude 提交于 4月 15, 2016

This is part of a patch series to migrate all of the workarounds for
commonly seen behavior from bad sinks in intel_dp_dpcd_read_wake() to drm's
DP helper.

Some sinks will just return garbage for the first aux tranaction they
receive when coming out of sleep mode, so we need to perform an additional
read before the actual read to workaround this.

			    Changes since v5
- If the throwaway read in drm_dp_dpcd_read() fails, return the error
  from that instead of continuing. This follows the same logic we do in
  drm_dp_dpcd_access() (e.g. the error from the first transaction may
  differ from the errors that proceeding attempts might return).
Signed-off-by: NLyude <cpaul@redhat.com>
Tested-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1460730335-5012-1-git-send-email-cpaul@redhat.com

f808f633

drm/dp_helper: Retry aux transactions on all errors · 82922da3

由 Lyude 提交于 4月 13, 2016

This is part of a patch series to migrate all of the workarounds for
commonly seen behavior from bad sinks in intel_dp_dpcd_read_wake() to
drm's DP helper.

We cannot rely on sinks NACKing or deferring when they can't receive
transactions, nor can we rely on any other sort of consistent error to
know when we should stop retrying. As such, we need to just retry
unconditionally on errors. We also make sure here to return the error we
encountered during the first transaction, since it's possible that
retrying the transaction might return a different error then we had
originally.

This, along with the previous patch, work around a weird bug with the
ThinkPad T560's and it's dock. When resuming the laptop, it appears that
there's a short period of time where we're unable to complete any aux
transactions, as they all immediately timeout. The only machine I'm able
to reproduce this on is the T560 as other production Skylake models seem
to be fine. The period during which AUX transactions fail appears to be
around 22ms long. AFAIK, the dock for the T560 never actually turns off,
the only difference is that it's in SST mode at the start of the resume
process, so it's unclear as to why it would need so much time to come
back up.

There's been a discussion on this issue going on for a while on the
intel-gfx mailing list about this that has, in addition to including
developers from Intel, also had the correspondence of one of the
hardware engineers for Intel:

http://www.spinics.net/lists/intel-gfx/msg88831.html
http://www.spinics.net/lists/intel-gfx/msg88410.html

We've already looked into a couple of possible explanations for the
problem:

- Calling intel_dp_mst_resume() before right fix.
  intel_runtime_pm_enable_interrupts(). This was the first fix I tried,
  and while it worked it definitely wasn't the right fix. This worked
  because DP aux transactions don't actually require interrupts to work:

	static uint32_t
	intel_dp_aux_wait_done(struct intel_dp *intel_dp, bool has_aux_irq)
	{
		struct intel_digital_port *intel_dig_port = dp_to_dig_port(intel_dp);
		struct drm_device *dev = intel_dig_port->base.base.dev;
		struct drm_i915_private *dev_priv = dev->dev_private;
		i915_reg_t ch_ctl = intel_dp->aux_ch_ctl_reg;
		uint32_t status;
		bool done;

	#define C (((status = I915_READ_NOTRACE(ch_ctl)) & DP_AUX_CH_CTL_SEND_BUSY) == 0)
		if (has_aux_irq)
			done = wait_event_timeout(dev_priv->gmbus_wait_queue, C,
						  msecs_to_jiffies_timeout(10));
		else
			done = wait_for_atomic(C, 10) == 0;
		if (!done)
			DRM_ERROR("dp aux hw did not signal timeout (has irq: %i)!\n",
				  has_aux_irq);
	#undef C

		return status;
	}

  When there's no interrupts enabled, we end up timing out on the
  wait_event_timeout() call, which causes us to check the DP status
  register once to see if the transaction was successful or not. Since
  this adds a 10ms delay to each aux transaction, it ends up adding a
  long enough delay to the resume process for aux transactions to become
  functional again. This gave us the illusion that enabling interrupts
  had something to do with making things work again, and put me on the
  wrong track for a while.

- Interrupts occurring when we try to perform the aux transactions
  required to put the dock back into MST mode. This isn't the problem,
  as the only interrupts I've observed that come during this timeout
  period are from the snd_hda_intel driver, and disabling that driver
  doesn't appear to change the behavior at all.

- Skylake's PSR block causing issues by performing aux transactions
  while we try to bring the dock out of MST mode. Disabling PSR through
  i915's command line options doesn't seem to change the behavior
  either, nor does preventing the DMC firmware from being loaded.

Since this investigation went on for about 2 weeks, we decided it would
be better for the time being to just workaround this issue by making
sure AUX transactions wait a short period of time before retrying.
Signed-off-by: NLyude <cpaul@redhat.com>
Tested-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1460559513-32280-3-git-send-email-cpaul@redhat.com

82922da3

drm/dp_helper: Always wait before retrying native aux transactions · e1083ff3

由 Lyude 提交于 4月 13, 2016

This is part of a patch series to migrate all of the workarounds for
commonly seen behavior from bad sinks in intel_dp_dpcd_read_wake() to
drm's DP helper.

Some sinks need some time during the process of resuming the system from
sleep before they're ready to handle transactions. While it would be
nice if they responded with NACKs in these scenarios, this isn't always
the case as a few sinks will just timeout on all of the transactions
they receive until they're ready.
Signed-off-by: NLyude <cpaul@redhat.com>
Tested-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1460559513-32280-2-git-send-email-cpaul@redhat.com

e1083ff3

openanolis / cloud-kernel 1 年多 前同步成功

openanolis / cloud-kernel
1 年多前同步成功