[Intel-gfx] [PATCH v2] drm/i915: Don't enable IPS when pixel rate exceeds 95% of cdclk

Jani Nikula jani.nikula at linux.intel.com
Thu Sep 18 13:56:22 CEST 2014


On Wed, 17 Sep 2014, Ville Syrjälä <ville.syrjala at linux.intel.com> wrote:
> On Wed, Sep 17, 2014 at 11:10:48AM -0300, Paulo Zanoni wrote:
>> 2014-09-17 11:05 GMT-03:00 Paulo Zanoni <przanoni at gmail.com>:
>> > 2014-09-15 4:22 GMT-03:00 Jani Nikula <jani.nikula at linux.intel.com>:
>> >> On Fri, 12 Sep 2014, Ville Syrjälä <ville.syrjala at linux.intel.com> wrote:
>> >>> On Fri, Sep 12, 2014 at 04:42:33PM +0100, Chris Wilson wrote:
>> >>>> On Fri, Sep 12, 2014 at 05:01:57PM +0300, ville.syrjala at linux.intel.com wrote:
>> >>>> > From: Ville Syrjälä <ville.syrjala at linux.intel.com>
>> >>>> >
>> >>>> > Bspec says we shouldn't enable IPS on BDW when the pipe pixel rate
>> >>>> > exceeds 95% of the core display clock. Apparently this can cause
>> >>>> > underruns.
>> >>>> >
>> >>>> > There's no similar restriction listed for HSW, so leave that one alone
>> >>>> > for now.
>> >>>> >
>> >>>> > v2: Add pipe_config_supports_ips() (Chris)
>> >>>> >
>> >>>> > Tested-by: Timo Aaltonen <tjaalton at ubuntu.com>
>> >>>> > Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=83497
>> >>>> > Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
>> >>>> > ---
>> >>>> >  drivers/gpu/drm/i915/intel_display.c | 21 +++++++++++++++++++--
>> >>>> >  drivers/gpu/drm/i915/intel_drv.h     |  1 +
>> >>>> >  drivers/gpu/drm/i915/intel_pm.c      | 16 +++++++---------
>> >>>> >  3 files changed, 27 insertions(+), 11 deletions(-)
>> >>>> >
>> >>>> > diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
>> >>>> > index 965eb3c..7809177 100644
>> >>>> > --- a/drivers/gpu/drm/i915/intel_display.c
>> >>>> > +++ b/drivers/gpu/drm/i915/intel_display.c
>> >>>> > @@ -5241,12 +5241,29 @@ retry:
>> >>>> >    return setup_ok ? 0 : -EINVAL;
>> >>>> >  }
>> >>>> >
>> >>>> > +static bool pipe_config_supports_ips(struct drm_i915_private *dev_priv,
>> >>>> > +                               struct intel_crtc_config *pipe_config)
>> >>>> > +{
>> >>>> > +  if (pipe_config->pipe_bpp > 24)
>> >>>> > +          return false;
>> >>>> > +
>> >>>> > +  /* HSW can handle pixel rate up to cdclk? */
>> >>>> > +  if (IS_HASWELL(dev_priv->dev))
>> >>>>
>> >>>> This only needs IS_HASWELL(dev_priv)
>> >>>
>> >>> old habits...
>> >>
>> >> Thanks to your old habits I didn't have to make any changes when pushing
>> >> this to drm-intel-fixes which is still old habit land. Thanks for the
>> >> patch and review.
>> 
>> And another detail: even if the register read worked, we'd have
>> printed a bad value since the cdclock is disabled at the moment we run
>> the function, so we'd return the FCLK frequency. So maybe we need to
>> cache the value of the "cdclk under normal display operation" and
>> reuse it here.
>
> Yeah. We already do that on VLV/CHV to some extent. We should just do
> it for all platforms. Although for this case what we'd need to do is
> precalculate the optimal cdclk during compute_config phase and use
> that value for these checks, and then during global_resources we
> actually change the cdclk to match the precomputed value.
>
> Also if someone takes this on they could also unify the ddi cdclk
> code to look more like the other platforms, and perhaps even implement
> support for changing the cdclk frequency on HSW/BDW ;)

I've dropped the commit from drm-intel-fixes and reopened the bug. We
need someone(tm) to look at this now.

BR,
Jani.



>
>> 
>> >
>> > This patches causes a regression on igt/pm_rpm/rte:
>> >
>> > [   44.871662] [drm:intel_dp_compute_config] DP link bw required
>> > 650358 available 1728000
>> > [   44.871666] ------------[ cut here ]------------
>> > [   44.871691] WARNING: CPU: 0 PID: 1745 at
>> > drivers/gpu/drm/i915/intel_uncore.c:47
>> > assert_device_not_suspended.isra.8+0x43/0x50 [i915]()
>> > [   44.871692] Device suspended
>> > [   44.871694] Modules linked in: hid_multitouch hid_sensor_hub
>> > snd_hda_codec_hdmi intel_rapl x86_pkg_temp_thermal intel_powerclamp
>> > efivars snd_hda_intel btusb snd_hda_controller snd_hda_codec snd_hwdep
>> > iwlmvm snd_pcm_oss snd_mixer_oss iwlwifi mei_me mei snd_pcm snd_timer
>> > int3403_thermal i2c_designware_platform i2c_designware_core acpi_pad
>> > fuse nls_utf8 nls_cp437 vfat fat i915 sdhci_pci drm_kms_helper e1000e
>> > drm sdhci_acpi sdhci
>> > [   44.871726] CPU: 0 PID: 1745 Comm: pm_rpm Not tainted
>> > 3.17.0-rc5.1409171019pz+ #1120
>> > [   44.871728] Hardware name: Intel Corporation Broadwell Client
>> > platform/Wilson Beach SDS, BIOS BDW-E2R1.86C.0072.R03.1405072127
>> > 05/07/2014
>> > [   44.871730]  0000000000000009 ffff8800aa763a90 ffffffff816ec803
>> > ffff8800aa763ad8
>> > [   44.871735]  ffff8800aa763ac8 ffffffff8107a0c8 ffff88023ec20068
>> > 0000000000130040
>> > [   44.871739]  ffff88023f12b3d8 0000000000130040 ffff88023ec20000
>> > ffff8800aa763b28
>> > [   44.871743] Call Trace:
>> > [   44.871749]  [<ffffffff816ec803>] dump_stack+0x4d/0x66
>> > [   44.871754]  [<ffffffff8107a0c8>] warn_slowpath_common+0x78/0xa0
>> > [   44.871758]  [<ffffffff8107a137>] warn_slowpath_fmt+0x47/0x50
>> > [   44.871783]  [<ffffffffa015a1f4>] ?
>> > intel_dp_compute_config+0x274/0x600 [i915]
>> > [   44.871803]  [<ffffffffa0122cf3>]
>> > assert_device_not_suspended.isra.8+0x43/0x50 [i915]
>> > [   44.871822]  [<ffffffffa0125a20>] gen6_read32+0x30/0x150 [i915]
>> > [   44.871844]  [<ffffffffa0154636>] intel_ddi_get_cdclk_freq+0xd6/0x140 [i915]
>> > [   44.871865]  [<ffffffffa0139a92>] __intel_set_mode+0x1672/0x1750 [i915]
>> > [   44.871886]  [<ffffffffa01418e1>] intel_set_mode+0x11/0x30 [i915]
>> > [   44.871906]  [<ffffffffa01429ed>] intel_crtc_set_config+0xa9d/0xeb0 [i915]
>> > [   44.871923]  [<ffffffffa0026283>]
>> > drm_mode_set_config_internal+0x63/0x100 [drm]
>> > [   44.871938]  [<ffffffffa002a7e3>] drm_mode_setcrtc+0x283/0x580 [drm]
>> > [   44.871948]  [<ffffffffa001c81f>] drm_ioctl+0x1df/0x6a0 [drm]
>> > [   44.871954]  [<ffffffff811e07b0>] do_vfs_ioctl+0x2e0/0x4e0
>> > [   44.871957]  [<ffffffff816f6af7>] ? sysret_check+0x1b/0x56
>> > [   44.871962]  [<ffffffff810bfb0d>] ? trace_hardirqs_on_caller+0x15d/0x200
>> > [   44.871966]  [<ffffffff811e0a31>] SyS_ioctl+0x81/0xa0
>> > [   44.871969]  [<ffffffff816f6ad2>] system_call_fastpath+0x16/0x1b
>> > [   44.871972] ---[ end trace 91bf8920a2c6b824 ]---
>> > [   44.871975] ------------[ cut here ]------------
>> > [   44.871994] WARNING: CPU: 0 PID: 1745 at
>> > drivers/gpu/drm/i915/intel_uncore.c:528
>> > hsw_unclaimed_reg_debug+0x6d/0x80 [i915]()
>> > [   44.871996] Unclaimed register detected before reading register 0x130040
>> > [   44.871997] Modules linked in: hid_multitouch hid_sensor_hub
>> > snd_hda_codec_hdmi intel_rapl x86_pkg_temp_thermal intel_powerclamp
>> > efivars snd_hda_intel btusb snd_hda_controller snd_hda_codec snd_hwdep
>> > iwlmvm snd_pcm_oss snd_mixer_oss iwlwifi mei_me mei snd_pcm snd_timer
>> > int3403_thermal i2c_designware_platform i2c_designware_core acpi_pad
>> > fuse nls_utf8 nls_cp437 vfat fat i915 sdhci_pci drm_kms_helper e1000e
>> > drm sdhci_acpi sdhci
>> > [   44.872025] CPU: 0 PID: 1745 Comm: pm_rpm Tainted: G        W
>> > 3.17.0-rc5.1409171019pz+ #1120
>> > [   44.872026] Hardware name: Intel Corporation Broadwell Client
>> > platform/Wilson Beach SDS, BIOS BDW-E2R1.86C.0072.R03.1405072127
>> > 05/07/2014
>> > [   44.872028]  0000000000000009 ffff8800aa763a88 ffffffff816ec803
>> > ffff8800aa763ad0
>> > [   44.872032]  ffff8800aa763ac0 ffffffff8107a0c8 ffff88023ec20000
>> > 0000000000130040
>> > [   44.872035]  ffff88023f12b3d8 0000000000130040 ffff88023ec20000
>> > ffff8800aa763b20
>> > [   44.872039] Call Trace:
>> > [   44.872042]  [<ffffffff816ec803>] dump_stack+0x4d/0x66
>> > [   44.872046]  [<ffffffff8107a0c8>] warn_slowpath_common+0x78/0xa0
>> > [   44.872049]  [<ffffffff8107a137>] warn_slowpath_fmt+0x47/0x50
>> > [   44.872068]  [<ffffffffa0122bbd>] hsw_unclaimed_reg_debug+0x6d/0x80 [i915]
>> > [   44.872087]  [<ffffffffa0125a41>] gen6_read32+0x51/0x150 [i915]
>> > [   44.872109]  [<ffffffffa0154636>] intel_ddi_get_cdclk_freq+0xd6/0x140 [i915]
>> > [   44.872129]  [<ffffffffa0139a92>] __intel_set_mode+0x1672/0x1750 [i915]
>> > [   44.872149]  [<ffffffffa01418e1>] intel_set_mode+0x11/0x30 [i915]
>> > [   44.872168]  [<ffffffffa01429ed>] intel_crtc_set_config+0xa9d/0xeb0 [i915]
>> > [   44.872182]  [<ffffffffa0026283>]
>> > drm_mode_set_config_internal+0x63/0x100 [drm]
>> > [   44.872196]  [<ffffffffa002a7e3>] drm_mode_setcrtc+0x283/0x580 [drm]
>> > [   44.872205]  [<ffffffffa001c81f>] drm_ioctl+0x1df/0x6a0 [drm]
>> > [   44.872210]  [<ffffffff811e07b0>] do_vfs_ioctl+0x2e0/0x4e0
>> > [   44.872213]  [<ffffffff816f6af7>] ? sysret_check+0x1b/0x56
>> > [   44.872218]  [<ffffffff810bfb0d>] ? trace_hardirqs_on_caller+0x15d/0x200
>> > [   44.872221]  [<ffffffff811e0a31>] SyS_ioctl+0x81/0xa0
>> > [   44.872224]  [<ffffffff816f6ad2>] system_call_fastpath+0x16/0x1b
>> > [   44.872226] ---[ end trace 91bf8920a2c6b825 ]---
>> > [   44.872228] ------------[ cut here ]------------
>> > [   44.872246] WARNING: CPU: 0 PID: 1745 at
>> > drivers/gpu/drm/i915/intel_uncore.c:528
>> > hsw_unclaimed_reg_debug+0x6d/0x80 [i915]()
>> > [   44.872248] Unclaimed register detected after reading register 0x130040
>> > [   44.872249] Modules linked in: hid_multitouch hid_sensor_hub
>> > snd_hda_codec_hdmi intel_rapl x86_pkg_temp_thermal intel_powerclamp
>> > efivars snd_hda_intel btusb snd_hda_controller snd_hda_codec snd_hwdep
>> > iwlmvm snd_pcm_oss snd_mixer_oss iwlwifi mei_me mei snd_pcm snd_timer
>> > int3403_thermal i2c_designware_platform i2c_designware_core acpi_pad
>> > fuse nls_utf8 nls_cp437 vfat fat i915 sdhci_pci drm_kms_helper e1000e
>> > drm sdhci_acpi sdhci
>> > [   44.872276] CPU: 0 PID: 1745 Comm: pm_rpm Tainted: G        W
>> > 3.17.0-rc5.1409171019pz+ #1120
>> > [   44.872277] Hardware name: Intel Corporation Broadwell Client
>> > platform/Wilson Beach SDS, BIOS BDW-E2R1.86C.0072.R03.1405072127
>> > 05/07/2014
>> > [   44.872279]  0000000000000009 ffff8800aa763a88 ffffffff816ec803
>> > ffff8800aa763ad0
>> > [   44.872282]  ffff8800aa763ac0 ffffffff8107a0c8 ffff88023ec20000
>> > 0000000000130040
>> > [   44.872286]  00000000ffffffff 0000000000130040 ffff88023ec20000
>> > ffff8800aa763b20
>> > [   44.872289] Call Trace:
>> > [   44.872293]  [<ffffffff816ec803>] dump_stack+0x4d/0x66
>> > [   44.872296]  [<ffffffff8107a0c8>] warn_slowpath_common+0x78/0xa0
>> > [   44.872299]  [<ffffffff8107a137>] warn_slowpath_fmt+0x47/0x50
>> > [   44.872318]  [<ffffffffa0122bbd>] hsw_unclaimed_reg_debug+0x6d/0x80 [i915]
>> > [   44.872335]  [<ffffffffa0125a7e>] gen6_read32+0x8e/0x150 [i915]
>> > [   44.872356]  [<ffffffffa0154636>] intel_ddi_get_cdclk_freq+0xd6/0x140 [i915]
>> > [   44.872376]  [<ffffffffa0139a92>] __intel_set_mode+0x1672/0x1750 [i915]
>> > [   44.872396]  [<ffffffffa01418e1>] intel_set_mode+0x11/0x30 [i915]
>> > [   44.872416]  [<ffffffffa01429ed>] intel_crtc_set_config+0xa9d/0xeb0 [i915]
>> > [   44.872429]  [<ffffffffa0026283>]
>> > drm_mode_set_config_internal+0x63/0x100 [drm]
>> > [   44.872443]  [<ffffffffa002a7e3>] drm_mode_setcrtc+0x283/0x580 [drm]
>> > [   44.872453]  [<ffffffffa001c81f>] drm_ioctl+0x1df/0x6a0 [drm]
>> > [   44.872458]  [<ffffffff811e07b0>] do_vfs_ioctl+0x2e0/0x4e0
>> > [   44.872461]  [<ffffffff816f6af7>] ? sysret_check+0x1b/0x56
>> > [   44.872465]  [<ffffffff810bfb0d>] ? trace_hardirqs_on_caller+0x15d/0x200
>> > [   44.872468]  [<ffffffff811e0a31>] SyS_ioctl+0x81/0xa0
>> > [   44.872471]  [<ffffffff816f6ad2>] system_call_fastpath+0x16/0x1b
>> > [   44.872473] ---[ end trace 91bf8920a2c6b826 ]---
>> > [   44.872512] [drm:intel_modeset_pipe_config] plane bpp: 24, pipe
>> > bpp: 18, dithering: 1
>> >
>> >>
>> >> BR,
>> >> Jani.
>> >>
>> >>
>> >>>
>> >>>>
>> >>>> > +          return true;
>> >>>> > +
>> >>>> > +  return ilk_pipe_pixel_rate(pipe_config) <=
>> >>>> > +          intel_ddi_get_cdclk_freq(dev_priv) * 95 / 100;
>> >>>>
>> >>>> Otherwise
>> >>>> Acked-by: Chris Wilson <chris at chris-wilson.co.uk>
>> >>>> -Chris
>> >>>>
>> >>>> --
>> >>>> Chris Wilson, Intel Open Source Technology Centre
>> >>>
>> >>> --
>> >>> Ville Syrjälä
>> >>> Intel OTC
>> >>> _______________________________________________
>> >>> Intel-gfx mailing list
>> >>> Intel-gfx at lists.freedesktop.org
>> >>> http://lists.freedesktop.org/mailman/listinfo/intel-gfx
>> >>
>> >> --
>> >> Jani Nikula, Intel Open Source Technology Center
>> >> _______________________________________________
>> >> Intel-gfx mailing list
>> >> Intel-gfx at lists.freedesktop.org
>> >> http://lists.freedesktop.org/mailman/listinfo/intel-gfx
>> >
>> >
>> >
>> > --
>> > Paulo Zanoni
>> 
>> 
>> 
>> -- 
>> Paulo Zanoni
>
> -- 
> Ville Syrjälä
> Intel OTC

-- 
Jani Nikula, Intel Open Source Technology Center



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