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[34.125.248.155]) by smtp.gmail.com with ESMTPSA id gz24-20020a17090b0ed800b0027d0af2e9c3sm6675469pjb.40.2023.10.17.11.03.44 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 17 Oct 2023 11:03:45 -0700 (PDT) From: Allen Ballway To: dri-devel@lists.freedesktop.org Cc: arun.r.murthy@intel.com, intel-gfx@lists.freedesktop.org, jani.nikula@linux.intel.com, linux-kernel@vger.kernel.org, Allen Ballway Subject: [PATCH] drm/i915/quirk: Add quirk for devices with incorrect PWM frequency Date: Tue, 17 Oct 2023 18:01:39 +0000 Message-ID: <20231017175728.1.Ibc6408a8ff1f334974104c5bcc25f2f35a57f36e@changeid> X-Mailer: git-send-email 2.42.0.655.g421f12c284-goog MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" Cyernet T10C has a bad default PWM frequency causing the display to strobe when the brightness is less than 100%. Create a new quirk to use the value from the BIOS rather than the default register value. Signed-off-by: Allen Ballway --- .../gpu/drm/i915/display/intel_backlight.c | 3 ++- drivers/gpu/drm/i915/display/intel_quirks.c | 26 +++++++++++++++++++ drivers/gpu/drm/i915/display/intel_quirks.h | 1 + 3 files changed, 29 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/i915/display/intel_backlight.c b/drivers/gpu/d= rm/i915/display/intel_backlight.c index 2e8f17c045222..c4dcfece9deca 100644 --- a/drivers/gpu/drm/i915/display/intel_backlight.c +++ b/drivers/gpu/drm/i915/display/intel_backlight.c @@ -1388,7 +1388,8 @@ static int vlv_setup_backlight(struct intel_connector= *connector, enum pipe pipe ctl =3D intel_de_read(i915, VLV_BLC_PWM_CTL(pipe)); panel->backlight.pwm_level_max =3D ctl >> 16; - if (!panel->backlight.pwm_level_max) + if (!panel->backlight.pwm_level_max || + intel_has_quirk(i915, QUIRK_IGNORE_DEFAULT_PWM_FREQUENCY)) panel->backlight.pwm_level_max =3D get_backlight_max_vbt(connector); if (!panel->backlight.pwm_level_max) diff --git a/drivers/gpu/drm/i915/display/intel_quirks.c b/drivers/gpu/drm/= i915/display/intel_quirks.c index a280448df771a..ff6cb499428ce 100644 --- a/drivers/gpu/drm/i915/display/intel_quirks.c +++ b/drivers/gpu/drm/i915/display/intel_quirks.c @@ -65,6 +65,12 @@ static void quirk_no_pps_backlight_power_hook(struct drm= _i915_private *i915) drm_info(&i915->drm, "Applying no pps backlight power quirk\n"); } +static void quirk_ignore_default_pwm_frequency(struct drm_i915_private *i9= 15) +{ + intel_set_quirk(i915, QUIRK_IGNORE_DEFAULT_PWM_FREQUENCY); + drm_info(&i915->drm, "Applying ignore default pwm frequency quirk"); +} + struct intel_quirk { int device; int subsystem_vendor; @@ -90,6 +96,12 @@ static int intel_dmi_no_pps_backlight(const struct dmi_s= ystem_id *id) return 1; } +static int intel_dmi_ignore_default_pwm_frequency(const struct dmi_system_= id *id) +{ + DRM_INFO("Default PWM frequency is incorrect and is overridden on %s\n", = id->ident); + return 1; +} + static const struct intel_dmi_quirk intel_dmi_quirks[] =3D { { .dmi_id_list =3D &(const struct dmi_system_id[]) { @@ -136,6 +148,20 @@ static const struct intel_dmi_quirk intel_dmi_quirks[]= =3D { }, .hook =3D quirk_no_pps_backlight_power_hook, }, + { + .dmi_id_list =3D &(const struct dmi_system_id[]) { + { + .callback =3D intel_dmi_ignore_default_pwm_frequency, + .ident =3D "Cybernet T10C Tablet", + .matches =3D {DMI_EXACT_MATCH(DMI_BOARD_VENDOR, + "Cybernet Manufacturing Inc."), + DMI_EXACT_MATCH(DMI_BOARD_NAME, "T10C Tablet"), + }, + }, + { } + }, + .hook =3D quirk_ignore_default_pwm_frequency, + }, }; static struct intel_quirk intel_quirks[] =3D { diff --git a/drivers/gpu/drm/i915/display/intel_quirks.h b/drivers/gpu/drm/= i915/display/intel_quirks.h index 10a4d163149fd..70589505e5a0e 100644 --- a/drivers/gpu/drm/i915/display/intel_quirks.h +++ b/drivers/gpu/drm/i915/display/intel_quirks.h @@ -17,6 +17,7 @@ enum intel_quirk_id { QUIRK_INVERT_BRIGHTNESS, QUIRK_LVDS_SSC_DISABLE, QUIRK_NO_PPS_BACKLIGHT_POWER_HOOK, + QUIRK_IGNORE_DEFAULT_PWM_FREQUENCY }; void intel_init_quirks(struct drm_i915_private *i915); -- 2.42.0.655.g421f12c284-goog