Re: [Intel-gfx] [RFC] [PATCH 00/14] HPD/connector-polling rework

2012-10-07 Thread Alex Deucher
On Thu, May 24, 2012 at 3:26 PM, Daniel Vetter daniel.vet...@ffwll.ch wrote:
 Hi all,

 I've got fed up with our sorry state of connector detection and rampant edid 
 re
 and rere-reading.

 This patch series lays the groundwork in the drm helpers so that drivers can
 avoid all this madness (at least on working hw) and properly cache the edid.

 With the additional changes for drm/i915, the edid is now read _once_ per plug
 event (or at boot-up/resume time). A further step would be to integrate the
 hotplug handling into the driver itself and only call -detect on the 
 connectors
 for which the irq handler received a hotplug event.

 By adding POLL_FORCE drivers can get back the old behaviour of calling 
 -detect
 every time probe_single_connector is called from userspace. I've splattered 
 that
 over all drivers where I've thought it might be required.

 Note though that setting this doesn't avoid all regressions - the regular 
 output
 poll work will still ignore any connectors with POLL_HPD set. If a driver/hw
 with broken hpd got away due to this, this will break stuff. But that should 
 be
 easy to fix by admitting the defeat and setting POLL_CONNECT|DISCONNECT
 directly.

 If other people want to convert over their drivers, the following steps are
 required:
 - Ensure that the connector status is unknown every time the driver could have
   missed a hpd event (e.g. after resume). drm_mode_config_reset will do that 
 for
   you.
 - Drop the POLL_FORCE flag for connectors where hdp is fully reliable.
 - Implement edid caching - that's a nice way to figure out whether hpd is
   actually reliable, because if it isn't, this step will ensure that you get 
 bug
   reports because the the edid won't ever get updated ;-)
 - Optionally teach the driver some smarts about which specific connectors
   actually got a hotplug event. Mostly useful on cheap hw (like intel's) that
   can't distinguish between hdmi and dp without trying some aux channel
   transfers.

 As you can guess from the patch series, I've discovered the hard way that i915
 sdvo support is totally broken. Tested on most of the intel machines I have 
 and
 also quickly on my radeon hd5000.

 Comments, flames, ideas and test reports highly welcome.

This set looks good to me.  Do you have plans to revive this?  At
least the common drm ones are much better than what we currently have.

Alex



 Cheers, Daniel

 Daniel Vetter (14):
   drm: extract drm_kms_helper_hotplug_event
   drm: handle HDP and polled connectors separately
   drm: introduce DRM_CONNECTOR_POLL_FORCE
   drm/i915: set POLL_FORCE for sdvo outputs
   drm: properly init/reset connector status
   drm: kill unnecessary calls to connector-detect
   drm: don't start the poll engine in probe_single_connector
   drm: don't unnecessarily enable the polling work
   drm: don't poll forced connectors
   drm/i915: cache crt edid
   drm/i915: cache dp edid
   drm/i915: cache hdmi edid
   drm/i915/sdvo: implement correct return value for -get_modes
   drm/i915: s/mdelay/msleep/ in the sdvo detect function

  drivers/gpu/drm/drm_crtc.c|6 ++-
  drivers/gpu/drm/drm_crtc_helper.c |   76 
 ++---
  drivers/gpu/drm/exynos/exynos_drm_connector.c |2 +
  drivers/gpu/drm/gma500/cdv_intel_crt.c|2 +
  drivers/gpu/drm/gma500/cdv_intel_hdmi.c   |2 +
  drivers/gpu/drm/gma500/mdfld_dsi_output.c |1 +
  drivers/gpu/drm/gma500/oaktrail_hdmi.c|2 +
  drivers/gpu/drm/gma500/psb_intel_sdvo.c   |2 +
  drivers/gpu/drm/i915/intel_crt.c  |   28 +++--
  drivers/gpu/drm/i915/intel_dp.c   |   47 +++
  drivers/gpu/drm/i915/intel_drv.h  |2 +
  drivers/gpu/drm/i915/intel_hdmi.c |   48 ++--
  drivers/gpu/drm/i915/intel_modes.c|   18 +-
  drivers/gpu/drm/i915/intel_sdvo.c |   45 +--
  drivers/gpu/drm/i915/intel_tv.c   |3 +-
  drivers/gpu/drm/nouveau/nouveau_connector.c   |1 +
  drivers/gpu/drm/radeon/radeon_connectors.c|5 ++
  drivers/gpu/drm/udl/udl_connector.c   |2 +
  drivers/staging/omapdrm/omap_connector.c  |2 +
  include/drm/drm_crtc.h|5 ++
  include/drm/drm_crtc_helper.h |1 +
  21 files changed, 208 insertions(+), 92 deletions(-)

 --
 1.7.7.6

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Re: [Intel-gfx] [RFC] [PATCH 00/14] HPD/connector-polling rework

2012-10-07 Thread Alex Deucher
On Thu, Oct 4, 2012 at 1:16 PM, Daniel Vetter dan...@ffwll.ch wrote:
 On Thu, Oct 04, 2012 at 12:07:01PM -0400, Alex Deucher wrote:
 On Thu, May 24, 2012 at 3:26 PM, Daniel Vetter daniel.vet...@ffwll.ch 
 wrote:
  Hi all,
 
  I've got fed up with our sorry state of connector detection and rampant 
  edid re
  and rere-reading.
 
  This patch series lays the groundwork in the drm helpers so that drivers 
  can
  avoid all this madness (at least on working hw) and properly cache the 
  edid.
 
  With the additional changes for drm/i915, the edid is now read _once_ per 
  plug
  event (or at boot-up/resume time). A further step would be to integrate the
  hotplug handling into the driver itself and only call -detect on the 
  connectors
  for which the irq handler received a hotplug event.
 
  By adding POLL_FORCE drivers can get back the old behaviour of calling 
  -detect
  every time probe_single_connector is called from userspace. I've 
  splattered that
  over all drivers where I've thought it might be required.
 
  Note though that setting this doesn't avoid all regressions - the regular 
  output
  poll work will still ignore any connectors with POLL_HPD set. If a 
  driver/hw
  with broken hpd got away due to this, this will break stuff. But that 
  should be
  easy to fix by admitting the defeat and setting POLL_CONNECT|DISCONNECT
  directly.
 
  If other people want to convert over their drivers, the following steps are
  required:
  - Ensure that the connector status is unknown every time the driver could 
  have
missed a hpd event (e.g. after resume). drm_mode_config_reset will do 
  that for
you.
  - Drop the POLL_FORCE flag for connectors where hdp is fully reliable.
  - Implement edid caching - that's a nice way to figure out whether hpd is
actually reliable, because if it isn't, this step will ensure that you 
  get bug
reports because the the edid won't ever get updated ;-)
  - Optionally teach the driver some smarts about which specific connectors
actually got a hotplug event. Mostly useful on cheap hw (like intel's) 
  that
can't distinguish between hdmi and dp without trying some aux channel
transfers.
 
  As you can guess from the patch series, I've discovered the hard way that 
  i915
  sdvo support is totally broken. Tested on most of the intel machines I 
  have and
  also quickly on my radeon hd5000.
 
  Comments, flames, ideas and test reports highly welcome.

 This set looks good to me.  Do you have plans to revive this?  At
 least the common drm ones are much better than what we currently have.

 The issue I've meanwhile discovered with hpd handling is that we really
 need the smarts in the driver to only do probing on native hdmi/dp outputs
 if we have a hpd irq for that specific port: Since we have 2 encoders for
 the same port, if e.g. dp is enabled and we do edid probing on the hdmi
 encoder/connector the display might get unhappy, which can happen even
 with these patches applied e.g. when pluggin in a 2nd display.

 So the new plan (for 3.8 hopefully) is to revamp the i915-internal hpd
 handling and keep on using the crtc helper stuff. For connectors with
 reliable hpd we'd simply return the tracked stated in -detect without
 touching the hw at all. So I don't think we need any changes in the
 hotplug/polling helper code. And looking again at these patches, they're a
 rather decent kludge and it's probably better to do this all in the
 drivers. Since the helper code sets the force parameter to false for all
 the background polling, you can just return any driver-internal cached
 state. And when force=true you could invalidate that cached state or do
 some additional (more expensive) detection.

Well the current code skips all hotplug event propagation if the poll
option is disabled (even for hpd capable connectors) which is fail so
the first few patches still seem like a win.  I guess you are not
planning to use any of the current common hpd code?  If so, do you
mind if we pull at least the first few patches in in the interim for
other drivers?

Alex


 In short: No plans to revive this, but certainly plans to improve the
 drm/i915 hpd handling.

 Cheers, Daniel
 --
 Daniel Vetter
 Software Engineer, Intel Corporation
 +41 (0) 79 365 57 48 - http://blog.ffwll.ch
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Re: [Intel-gfx] [RFC] [PATCH 00/14] HPD/connector-polling rework

2012-10-04 Thread Daniel Vetter
On Thu, Oct 04, 2012 at 12:07:01PM -0400, Alex Deucher wrote:
 On Thu, May 24, 2012 at 3:26 PM, Daniel Vetter daniel.vet...@ffwll.ch wrote:
  Hi all,
 
  I've got fed up with our sorry state of connector detection and rampant 
  edid re
  and rere-reading.
 
  This patch series lays the groundwork in the drm helpers so that drivers can
  avoid all this madness (at least on working hw) and properly cache the edid.
 
  With the additional changes for drm/i915, the edid is now read _once_ per 
  plug
  event (or at boot-up/resume time). A further step would be to integrate the
  hotplug handling into the driver itself and only call -detect on the 
  connectors
  for which the irq handler received a hotplug event.
 
  By adding POLL_FORCE drivers can get back the old behaviour of calling 
  -detect
  every time probe_single_connector is called from userspace. I've splattered 
  that
  over all drivers where I've thought it might be required.
 
  Note though that setting this doesn't avoid all regressions - the regular 
  output
  poll work will still ignore any connectors with POLL_HPD set. If a driver/hw
  with broken hpd got away due to this, this will break stuff. But that 
  should be
  easy to fix by admitting the defeat and setting POLL_CONNECT|DISCONNECT
  directly.
 
  If other people want to convert over their drivers, the following steps are
  required:
  - Ensure that the connector status is unknown every time the driver could 
  have
missed a hpd event (e.g. after resume). drm_mode_config_reset will do 
  that for
you.
  - Drop the POLL_FORCE flag for connectors where hdp is fully reliable.
  - Implement edid caching - that's a nice way to figure out whether hpd is
actually reliable, because if it isn't, this step will ensure that you 
  get bug
reports because the the edid won't ever get updated ;-)
  - Optionally teach the driver some smarts about which specific connectors
actually got a hotplug event. Mostly useful on cheap hw (like intel's) 
  that
can't distinguish between hdmi and dp without trying some aux channel
transfers.
 
  As you can guess from the patch series, I've discovered the hard way that 
  i915
  sdvo support is totally broken. Tested on most of the intel machines I have 
  and
  also quickly on my radeon hd5000.
 
  Comments, flames, ideas and test reports highly welcome.
 
 This set looks good to me.  Do you have plans to revive this?  At
 least the common drm ones are much better than what we currently have.

The issue I've meanwhile discovered with hpd handling is that we really
need the smarts in the driver to only do probing on native hdmi/dp outputs
if we have a hpd irq for that specific port: Since we have 2 encoders for
the same port, if e.g. dp is enabled and we do edid probing on the hdmi
encoder/connector the display might get unhappy, which can happen even
with these patches applied e.g. when pluggin in a 2nd display.

So the new plan (for 3.8 hopefully) is to revamp the i915-internal hpd
handling and keep on using the crtc helper stuff. For connectors with
reliable hpd we'd simply return the tracked stated in -detect without
touching the hw at all. So I don't think we need any changes in the
hotplug/polling helper code. And looking again at these patches, they're a
rather decent kludge and it's probably better to do this all in the
drivers. Since the helper code sets the force parameter to false for all
the background polling, you can just return any driver-internal cached
state. And when force=true you could invalidate that cached state or do
some additional (more expensive) detection.

In short: No plans to revive this, but certainly plans to improve the
drm/i915 hpd handling.

Cheers, Daniel
-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch
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[Intel-gfx] [RFC] [PATCH 00/14] HPD/connector-polling rework

2012-05-24 Thread Daniel Vetter
Hi all,

I've got fed up with our sorry state of connector detection and rampant edid re
and rere-reading.

This patch series lays the groundwork in the drm helpers so that drivers can
avoid all this madness (at least on working hw) and properly cache the edid.

With the additional changes for drm/i915, the edid is now read _once_ per plug
event (or at boot-up/resume time). A further step would be to integrate the
hotplug handling into the driver itself and only call -detect on the connectors
for which the irq handler received a hotplug event.

By adding POLL_FORCE drivers can get back the old behaviour of calling -detect
every time probe_single_connector is called from userspace. I've splattered that
over all drivers where I've thought it might be required.

Note though that setting this doesn't avoid all regressions - the regular output
poll work will still ignore any connectors with POLL_HPD set. If a driver/hw
with broken hpd got away due to this, this will break stuff. But that should be
easy to fix by admitting the defeat and setting POLL_CONNECT|DISCONNECT
directly.

If other people want to convert over their drivers, the following steps are
required:
- Ensure that the connector status is unknown every time the driver could have
  missed a hpd event (e.g. after resume). drm_mode_config_reset will do that for
  you.
- Drop the POLL_FORCE flag for connectors where hdp is fully reliable.
- Implement edid caching - that's a nice way to figure out whether hpd is
  actually reliable, because if it isn't, this step will ensure that you get bug
  reports because the the edid won't ever get updated ;-)
- Optionally teach the driver some smarts about which specific connectors
  actually got a hotplug event. Mostly useful on cheap hw (like intel's) that
  can't distinguish between hdmi and dp without trying some aux channel
  transfers.

As you can guess from the patch series, I've discovered the hard way that i915
sdvo support is totally broken. Tested on most of the intel machines I have and
also quickly on my radeon hd5000.

Comments, flames, ideas and test reports highly welcome.

Cheers, Daniel

Daniel Vetter (14):
  drm: extract drm_kms_helper_hotplug_event
  drm: handle HDP and polled connectors separately
  drm: introduce DRM_CONNECTOR_POLL_FORCE
  drm/i915: set POLL_FORCE for sdvo outputs
  drm: properly init/reset connector status
  drm: kill unnecessary calls to connector-detect
  drm: don't start the poll engine in probe_single_connector
  drm: don't unnecessarily enable the polling work
  drm: don't poll forced connectors
  drm/i915: cache crt edid
  drm/i915: cache dp edid
  drm/i915: cache hdmi edid
  drm/i915/sdvo: implement correct return value for -get_modes
  drm/i915: s/mdelay/msleep/ in the sdvo detect function

 drivers/gpu/drm/drm_crtc.c|6 ++-
 drivers/gpu/drm/drm_crtc_helper.c |   76 ++---
 drivers/gpu/drm/exynos/exynos_drm_connector.c |2 +
 drivers/gpu/drm/gma500/cdv_intel_crt.c|2 +
 drivers/gpu/drm/gma500/cdv_intel_hdmi.c   |2 +
 drivers/gpu/drm/gma500/mdfld_dsi_output.c |1 +
 drivers/gpu/drm/gma500/oaktrail_hdmi.c|2 +
 drivers/gpu/drm/gma500/psb_intel_sdvo.c   |2 +
 drivers/gpu/drm/i915/intel_crt.c  |   28 +++--
 drivers/gpu/drm/i915/intel_dp.c   |   47 +++
 drivers/gpu/drm/i915/intel_drv.h  |2 +
 drivers/gpu/drm/i915/intel_hdmi.c |   48 ++--
 drivers/gpu/drm/i915/intel_modes.c|   18 +-
 drivers/gpu/drm/i915/intel_sdvo.c |   45 +--
 drivers/gpu/drm/i915/intel_tv.c   |3 +-
 drivers/gpu/drm/nouveau/nouveau_connector.c   |1 +
 drivers/gpu/drm/radeon/radeon_connectors.c|5 ++
 drivers/gpu/drm/udl/udl_connector.c   |2 +
 drivers/staging/omapdrm/omap_connector.c  |2 +
 include/drm/drm_crtc.h|5 ++
 include/drm/drm_crtc_helper.h |1 +
 21 files changed, 208 insertions(+), 92 deletions(-)

-- 
1.7.7.6

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