[Intel-gfx] [PATCH] drm/i915/bios: add DP max link rate to VBT child device struct

[Ville Syrjälä]

On Thu, Jan 18, 2018 at 05:31:45PM +0200, Jani Nikula wrote:
> On Thu, 18 Jan 2018, David Weinehall <david.weinehall at linux.intel.com> wrote:
> > On Thu, Jan 18, 2018 at 05:04:59PM +0200, Jani Nikula wrote:
> >> Update VBT defs to reflect revision 216. While at it, default the
> >> expected child device struct size to sizeof the size rather than a
> >> hardcoded value.
> >> 
> >> Cc: Rodrigo Vivi <rodrigo.vivi at intel.com>
> >> Signed-off-by: Jani Nikula <jani.nikula at intel.com>
> >
> >
> >> ---
> >>  drivers/gpu/drm/i915/intel_bios.c     | 8 +++++---
> >>  drivers/gpu/drm/i915/intel_vbt_defs.h | 2 ++
> >>  2 files changed, 7 insertions(+), 3 deletions(-)
> >> 
> >> diff --git a/drivers/gpu/drm/i915/intel_bios.c b/drivers/gpu/drm/i915/intel_bios.c
> >> index 51108ffc28d1..b820d595ebc8 100644
> >> --- a/drivers/gpu/drm/i915/intel_bios.c
> >> +++ b/drivers/gpu/drm/i915/intel_bios.c
> >> @@ -1323,11 +1323,13 @@ parse_general_definitions(struct drm_i915_private *dev_priv,
> >>  		expected_size = LEGACY_CHILD_DEVICE_CONFIG_SIZE;
> >>  	} else if (bdb->version == 195) {
> >>  		expected_size = 37;
> >> -	} else if (bdb->version <= 197) {
> >> +	} else if (bdb->version <= 215) {
> >>  		expected_size = 38;
> >> +	} else if (bdb->version <= 216) {
> >> +		expected_size = 39;
> >>  	} else {
> >> -		expected_size = 38;
> >> -		BUILD_BUG_ON(sizeof(*child) < 38);
> >> +		expected_size = sizeof(*child);
> >> +		BUILD_BUG_ON(sizeof(*child) < 39);
> >>  		DRM_DEBUG_DRIVER("Expected child device config size for VBT version %u not known; assuming %u\n",
> >>  				 bdb->version, expected_size);
> >>  	}
> >> diff --git a/drivers/gpu/drm/i915/intel_vbt_defs.h b/drivers/gpu/drm/i915/intel_vbt_defs.h
> >> index e3d7745a9151..bbb173e116b3 100644
> >> --- a/drivers/gpu/drm/i915/intel_vbt_defs.h
> >> +++ b/drivers/gpu/drm/i915/intel_vbt_defs.h
> >> @@ -412,6 +412,8 @@ struct child_device_config {
> >>  	u16 dp_gpio_pin_num;					/* 195 */
> >>  	u8 dp_iboost_level:4;					/* 196 */
> >>  	u8 hdmi_iboost_level:4;					/* 196 */
> >> +	u8 dp_max_link_rate_reserved:6;				/* 216 */
> >> +	u8 dp_max_link_rate:2;					/* 216 CNL+ */
> >
> > Isn't the bitorder wrong here?
> 
> *facepalm*

Maybe we should add a comment specifying how we expect them
bitfields to work here. I can never remember which way they go.

-- 
Ville Syrjälä
Intel OTC