[PATCH v3 2/2] drm/i915/display: Increase Fast Wake Sync length as a quirk

Hogander, Jouni jouni.hogander at intel.com
Tue Sep 3 05:07:30 UTC 2024


On Mon, 2024-09-02 at 11:33 +0300, Jani Nikula wrote:
> On Mon, 02 Sep 2024, Jouni Högander <jouni.hogander at intel.com> wrote:
> > In commit "drm/i915/display: Increase number of fast wake precharge
> > pulses"
> > we were increasing Fast Wake sync pulse length to fix problems
> > observed on
> > Dell Precision 5490 laptop with AUO panel. Later we have observed
> > this is
> > causing problems on other panels.
> > 
> > Fix these problems by increasing Fast Wake sync pulse length as a
> > quirk
> > applied for Dell Precision 5490 with problematic panel.
> > 
> > Fixes: f77772866385 ("drm/i915/display: Increase number of fast
> > wake precharge pulses")
> > Cc: Ville Syrjälä <ville.syrjala at linux.intel.com>
> > Closes: http://gitlab.freedesktop.org/drm/i915/kernel/-/issues/9739
> > Closes: https://gitlab.freedesktop.org/drm/xe/kernel/-/issues/2246
> > Closes:
> > https://gitlab.freedesktop.org/drm/i915/kernel/-/issues/11762
> > Signed-off-by: Jouni Högander <jouni.hogander at intel.com>
> 
> Cc: <stable at vger.kernel.org> # v6.10+
> Reviewed-by: Jani Nikula <jani.nikula at intel.com>

Thank you Jani for reviewing my patches. These are now pushed to drm-
intel-next.

BR,

Jouni Högander

> 
> 
> > ---
> >  drivers/gpu/drm/i915/display/intel_alpm.c   |  2 +-
> >  drivers/gpu/drm/i915/display/intel_dp_aux.c | 16 +++++++++++-----
> >  drivers/gpu/drm/i915/display/intel_dp_aux.h |  2 +-
> >  drivers/gpu/drm/i915/display/intel_quirks.c | 17 +++++++++++++++++
> >  drivers/gpu/drm/i915/display/intel_quirks.h |  1 +
> >  5 files changed, 31 insertions(+), 7 deletions(-)
> > 
> > diff --git a/drivers/gpu/drm/i915/display/intel_alpm.c
> > b/drivers/gpu/drm/i915/display/intel_alpm.c
> > index 82ee778b2efe9..186cf4833f716 100644
> > --- a/drivers/gpu/drm/i915/display/intel_alpm.c
> > +++ b/drivers/gpu/drm/i915/display/intel_alpm.c
> > @@ -228,7 +228,7 @@ bool intel_alpm_compute_params(struct intel_dp
> > *intel_dp,
> >         int tfw_exit_latency = 20; /* eDP spec */
> >         int phy_wake = 4;          /* eDP spec */
> >         int preamble = 8;          /* eDP spec */
> > -       int precharge = intel_dp_aux_fw_sync_len() - preamble;
> > +       int precharge = intel_dp_aux_fw_sync_len(intel_dp) -
> > preamble;
> >         u8 max_wake_lines;
> >  
> >         io_wake_time = max(precharge,
> > io_buffer_wake_time(crtc_state)) +
> > diff --git a/drivers/gpu/drm/i915/display/intel_dp_aux.c
> > b/drivers/gpu/drm/i915/display/intel_dp_aux.c
> > index cbc817bb0cc3e..6420da69f3bbc 100644
> > --- a/drivers/gpu/drm/i915/display/intel_dp_aux.c
> > +++ b/drivers/gpu/drm/i915/display/intel_dp_aux.c
> > @@ -13,6 +13,7 @@
> >  #include "intel_dp_aux.h"
> >  #include "intel_dp_aux_regs.h"
> >  #include "intel_pps.h"
> > +#include "intel_quirks.h"
> >  #include "intel_tc.h"
> >  
> >  #define AUX_CH_NAME_BUFSIZE    6
> > @@ -142,16 +143,21 @@ static int intel_dp_aux_sync_len(void)
> >         return precharge + preamble;
> >  }
> >  
> > -int intel_dp_aux_fw_sync_len(void)
> > +int intel_dp_aux_fw_sync_len(struct intel_dp *intel_dp)
> >  {
> > +       int precharge = 10; /* 10-16 */
> > +       int preamble = 8;
> > +
> >         /*
> >          * We faced some glitches on Dell Precision 5490 MTL laptop
> > with panel:
> >          * "Manufacturer: AUO, Model: 63898" when using HW default
> > 18. Using 20
> >          * is fixing these problems with the panel. It is still
> > within range
> > -        * mentioned in eDP specification.
> > +        * mentioned in eDP specification. Increasing Fast Wake
> > sync length is
> > +        * causing problems with other panels: increase length as a
> > quirk for
> > +        * this specific laptop.
> >          */
> > -       int precharge = 12; /* 10-16 */
> > -       int preamble = 8;
> > +       if (intel_has_dpcd_quirk(intel_dp, QUIRK_FW_SYNC_LEN))
> > +               precharge += 2;
> >  
> >         return precharge + preamble;
> >  }
> > @@ -211,7 +217,7 @@ static u32 skl_get_aux_send_ctl(struct intel_dp
> > *intel_dp,
> >                 DP_AUX_CH_CTL_TIME_OUT_MAX |
> >                 DP_AUX_CH_CTL_RECEIVE_ERROR |
> >                 DP_AUX_CH_CTL_MESSAGE_SIZE(send_bytes) |
> > -
> >                DP_AUX_CH_CTL_FW_SYNC_PULSE_SKL(intel_dp_aux_fw_sync_
> > len()) |
> > +               DP_AUX_CH_CTL_FW_SYNC_PULSE_SKL(intel_dp_aux_fw_syn
> > c_len(intel_dp)) |
> >                 DP_AUX_CH_CTL_SYNC_PULSE_SKL(intel_dp_aux_sync_len(
> > ));
> >  
> >         if (intel_tc_port_in_tbt_alt_mode(dig_port))
> > diff --git a/drivers/gpu/drm/i915/display/intel_dp_aux.h
> > b/drivers/gpu/drm/i915/display/intel_dp_aux.h
> > index 76d1f2ed7c2f4..593f58fafab71 100644
> > --- a/drivers/gpu/drm/i915/display/intel_dp_aux.h
> > +++ b/drivers/gpu/drm/i915/display/intel_dp_aux.h
> > @@ -20,6 +20,6 @@ enum aux_ch intel_dp_aux_ch(struct intel_encoder
> > *encoder);
> >  
> >  void intel_dp_aux_irq_handler(struct drm_i915_private *i915);
> >  u32 intel_dp_aux_pack(const u8 *src, int src_bytes);
> > -int intel_dp_aux_fw_sync_len(void);
> > +int intel_dp_aux_fw_sync_len(struct intel_dp *intel_dp);
> >  
> >  #endif /* __INTEL_DP_AUX_H__ */
> > diff --git a/drivers/gpu/drm/i915/display/intel_quirks.c
> > b/drivers/gpu/drm/i915/display/intel_quirks.c
> > index bce1f67c918bb..29b56d53a340a 100644
> > --- a/drivers/gpu/drm/i915/display/intel_quirks.c
> > +++ b/drivers/gpu/drm/i915/display/intel_quirks.c
> > @@ -70,6 +70,14 @@ static void
> > quirk_no_pps_backlight_power_hook(struct intel_display *display)
> >         drm_info(display->drm, "Applying no pps backlight power
> > quirk\n");
> >  }
> >  
> > +static void quirk_fw_sync_len(struct intel_dp *intel_dp)
> > +{
> > +       struct intel_display *display = to_intel_display(intel_dp);
> > +
> > +       intel_set_dpcd_quirk(intel_dp, QUIRK_FW_SYNC_LEN);
> > +       drm_info(display->drm, "Applying Fast Wake sync pulse count
> > quirk\n");
> > +}
> > +
> >  struct intel_quirk {
> >         int device;
> >         int subsystem_vendor;
> > @@ -224,6 +232,15 @@ static struct intel_quirk intel_quirks[] = {
> >  };
> >  
> >  static struct intel_dpcd_quirk intel_dpcd_quirks[] = {
> > +       /* Dell Precision 5490 */
> > +       {
> > +               .device = 0x7d55,
> > +               .subsystem_vendor = 0x1028,
> > +               .subsystem_device = 0x0cc7,
> > +               .sink_oui = SINK_OUI(0x38, 0xec, 0x11),
> > +               .hook = quirk_fw_sync_len,
> > +       },
> > +
> >  };
> >  
> >  void intel_init_quirks(struct intel_display *display)
> > diff --git a/drivers/gpu/drm/i915/display/intel_quirks.h
> > b/drivers/gpu/drm/i915/display/intel_quirks.h
> > index c8db50b9ab74d..cafdebda75354 100644
> > --- a/drivers/gpu/drm/i915/display/intel_quirks.h
> > +++ b/drivers/gpu/drm/i915/display/intel_quirks.h
> > @@ -19,6 +19,7 @@ enum intel_quirk_id {
> >         QUIRK_INVERT_BRIGHTNESS,
> >         QUIRK_LVDS_SSC_DISABLE,
> >         QUIRK_NO_PPS_BACKLIGHT_POWER_HOOK,
> > +       QUIRK_FW_SYNC_LEN,
> >  };
> >  
> >  void intel_init_quirks(struct intel_display *display);
> 



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