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[34.125.199.175]) by smtp.gmail.com with ESMTPSA id t9-20020a17090ad14900b00280976d4ce3sm1960160pjw.37.2023.11.10.11.14.01 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 10 Nov 2023 11:14:02 -0800 (PST) From: Allen Ballway To: dmitry.torokhov@gmail.com Cc: ballway@chromium.org, dri-devel@lists.freedesktop.org, intel-gfx@lists.freedesktop.org, linux-kernel@vger.kernel.org Subject: [PATCH v2] drm/i915/quirk: Add quirk for devices with incorrect PWM frequency Date: Fri, 10 Nov 2023 19:13:37 +0000 Message-ID: <20231110191340.4157610-1-ballway@chromium.org> X-Mailer: git-send-email 2.42.0.869.gea05f2083d-goog In-Reply-To: References: 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 --- V1 -> V2: Fix style issues. .../gpu/drm/i915/display/intel_backlight.c | 6 +++-- drivers/gpu/drm/i915/display/intel_quirks.c | 26 +++++++++++++++++++ drivers/gpu/drm/i915/display/intel_quirks.h | 1 + 3 files changed, 31 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/i915/display/intel_backlight.c b/drivers/gpu/d= rm/i915/display/intel_backlight.c index 2e8f17c045222..b4171952343eb 100644 --- a/drivers/gpu/drm/i915/display/intel_backlight.c +++ b/drivers/gpu/drm/i915/display/intel_backlight.c @@ -1385,8 +1385,10 @@ static int vlv_setup_backlight(struct intel_connecto= r *connector, enum pipe pipe ctl2 =3D intel_de_read(i915, VLV_BLC_PWM_CTL2(pipe)); panel->backlight.active_low_pwm =3D ctl2 & BLM_POLARITY_I965; - ctl =3D intel_de_read(i915, VLV_BLC_PWM_CTL(pipe)); - panel->backlight.pwm_level_max =3D ctl >> 16; + if (!intel_has_quirk(i915, QUIRK_IGNORE_DEFAULT_PWM_FREQUENCY)) { + 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) panel->backlight.pwm_level_max =3D get_backlight_max_vbt(connector); 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..ca34dacf0c242 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); -- 2.42.0.869.gea05f2083d-goog