On Fri, Sept. 11, 2020, 2:21 p.m. Ville Syrjälä wrote: >On Thu, Aug 27, 2020 at 01:51:29PM +0800, Lee Shawn C wrote: >> Customer report random display flicker issue on Nightfury board. >> And we found this problem might be caused by VT-d and FBC are both >> enabled. According to sighting report, it recommend to turn >> drm/i915/fbc: disable FBC on Nightfury board >> >> Customer report random display flicker issue on Nightfury board. >> And we found this problem might be caused by VT-d and FBC are both >> enabled. According to sighting report, it recommend to turn FBC off to >> workaround this kind of issue. >> >> This change refer to DMI BOARD_VENDOR and BOARD_NAME information to >> disable FBC. > >What is this "nightfury board" exactly?
It is chrome os project on CML platform. The board name is "nightfury". > >I think we're missing at least one fbc vs. vt-d w/a on some kbl/cfl/etc. era >platforms: >git://github.com/vsyrjala/linux.git vtd_wa_1142 > >> >> Cc: Ville Syrjälä <[email protected]> >> Cc: Rodrigo Vivi <[email protected]> >> Cc: Mika Kuoppala <[email protected]> >> Cc: Jani Nikula <[email protected]> >> Cc: William Tseng <[email protected]> >> Cc: Cooper Chiou <[email protected]> >> Signed-off-by: Lee Shawn C <[email protected]> >> --- >> drivers/gpu/drm/i915/display/intel_fbc.c | 22 ++++++++++++++++++++++ >> 1 file changed, 22 insertions(+) >> >> diff --git a/drivers/gpu/drm/i915/display/intel_fbc.c >> b/drivers/gpu/drm/i915/display/intel_fbc.c >> index 327af428d73f..20660fdbab36 100644 >> --- a/drivers/gpu/drm/i915/display/intel_fbc.c >> +++ b/drivers/gpu/drm/i915/display/intel_fbc.c >> @@ -39,6 +39,7 @@ >> */ >> >> #include <drm/drm_fourcc.h> >> +#include <linux/dmi.h> >> >> #include "i915_drv.h" >> #include "i915_trace.h" >> @@ -1439,6 +1440,24 @@ static int intel_sanitize_fbc_option(struct >> drm_i915_private *dev_priv) >> return 0; >> } >> >> +static int intel_fbc_vtd_callback(const struct dmi_system_id *id) { >> + DRM_DEBUG_KMS("Disabling FBC to prevent screen flicker on %s device\n", >> id->ident); >> + return 1; >> +} >> + >> +static const struct dmi_system_id intel_fbc_vtd_detect[] = { >> + { >> + .callback = intel_fbc_vtd_callback, >> + .ident = "Google Nightfury", >> + .matches = { >> + DMI_MATCH(DMI_BOARD_VENDOR, "Google"), >> + DMI_MATCH(DMI_BOARD_NAME, "Nightfury"), >> + }, >> + }, >> + { } >> +}; >> + >> static bool need_fbc_vtd_wa(struct drm_i915_private *dev_priv) { >> /* WaFbcTurnOffFbcWhenHyperVisorIsUsed:skl,bxt */ @@ -1450,6 +1469,9 >> @@ static bool need_fbc_vtd_wa(struct drm_i915_private *dev_priv) >> return true; >> } >> >> + if (dmi_check_system(intel_fbc_vtd_detect)) >> + return true; >> + >> return false; >> } >> >> -- >> 2.17.1 > >-- >Ville Syrjälä >Intel Best regards, Shawn _______________________________________________ Intel-gfx mailing list [email protected] https://lists.freedesktop.org/mailman/listinfo/intel-gfx
