Boot params quirks_set and quirks_mask allow the user to enable or inhibit any dmi-matched quirks, overriding the dmi match table. Examples:

i915.quirks_set=0x2 - enables QUIRK_LVDS_SSC_DISABLE i915.quirks_set=0x8 - enables QUIRK_NO_PCH_PWM_ENABLE i915.quirks_mask=0x8 - disables QUIRK_NO_PCH_PWM_ENABLE i915.quirks_mask=0xFF - disables all quirks

Signed-off-by: Kamal Mostafa kamal@canonical.com Cc: stable@vger.kernel.org --- drivers/gpu/drm/i915/intel_display.c | 15 +++++++++++++++ 1 file changed, 15 insertions(+)

diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c index d88057e..a6af11c 100644 --- a/drivers/gpu/drm/i915/intel_display.c +++ b/drivers/gpu/drm/i915/intel_display.c @@ -10028,8 +10028,19 @@ static struct intel_quirk intel_quirks[] = { { 0x0166, 0x1028, 0x058b, quirk_no_pcm_pwm_enable }, };

+unsigned long i915_quirks_set __read_mostly = 0; +module_param_named(quirks_set, i915_quirks_set, ulong, 0600); +MODULE_PARM_DESC(quirks_set, + "Enable specified quirks bits."); + +unsigned long i915_quirks_mask __read_mostly = 0; +module_param_named(quirks_mask, i915_quirks_mask, ulong, 0600); +MODULE_PARM_DESC(quirks_mask, + "Disable specified quirks bits (override dmi match)."); + static void intel_init_quirks(struct drm_device *dev) { + struct drm_i915_private *dev_priv = dev->dev_private; struct pci_dev *d = dev->pdev; int i;

@@ -10047,6 +10058,10 @@ static void intel_init_quirks(struct drm_device *dev) if (dmi_check_system(*intel_dmi_quirks[i].dmi_id_list) != 0) intel_dmi_quirks[i].hook(dev); } + + /* handle user-specified quirks overrides */ + dev_priv->quirks |= i915_quirks_set; + dev_priv->quirks &= ~i915_quirks_mask; }

/* Disable the VGA plane that we never use */