[PATCH] drm/amd/display: eDP fast bootup does not work for pre-raven asic

[Paul Menzel]

Dear Hersen, dear Leo,


Some nitpicks. Could you not put the problem statement in the commit
message summary, but the solution? For example:

> Fix eDP fast bootup for pre-raven asics

On 01/14/19 23:36, sunpeng.li at amd.com wrote:
> From: hersen wu <hersenxs.wu at amd.com>
> 
> [Why] bios will light up eDP before sw driver loaded. sw driver will

*is* loaded

> check if eDP lighted up by bios by reading BIOS_SCRATCH_3. If yes,
> sw driver will not power down eDP power, phy to save time.
> definition of BIOS_SCRATCH_3 are missed for pre-raven asic. this

are *missing*

> cuase eDP fast boot up not work. for some eDP panel, even AMD dp tx

*causes* … *to* not work.

> send NoVideoStream_flag =1 and dpcd 0x600=2, eDP rx may not handle

send*s*?

> properly. this may cause short period flash on screen.

Is that in the eDP specification?

> [How] add definition of BIOS_SCRATCH_3 for all asic

How was this tested?

> CC: Harry Wentland <harry.wentland at amd.com>
> Signed-off-by: hersen wu <hersenxs.wu at amd.com>
> Reviewed-by: Charlene Liu <Charlene.Liu at amd.com>
> Acked-by: Yongqiang Sun <yongqiang.sun at amd.com>
> Acked-by: Leo Li <sunpeng.li at amd.com>
> ---
>  drivers/gpu/drm/amd/display/dc/bios/bios_parser_helper.c | 3 +--
>  drivers/gpu/drm/amd/display/dc/dce100/dce100_resource.c  | 2 ++
>  drivers/gpu/drm/amd/display/dc/dce110/dce110_resource.c  | 2 ++
>  drivers/gpu/drm/amd/display/dc/dce112/dce112_resource.c  | 2 ++
>  drivers/gpu/drm/amd/display/dc/dce120/dce120_resource.c  | 1 +
>  drivers/gpu/drm/amd/display/dc/dce80/dce80_resource.c    | 2 ++
>  6 files changed, 10 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/gpu/drm/amd/display/dc/bios/bios_parser_helper.c b/drivers/gpu/drm/amd/display/dc/bios/bios_parser_helper.c
> index fdda8aa..d8275ceb 100644
> --- a/drivers/gpu/drm/amd/display/dc/bios/bios_parser_helper.c
> +++ b/drivers/gpu/drm/amd/display/dc/bios/bios_parser_helper.c
> @@ -83,8 +83,7 @@ uint32_t bios_get_vga_enabled_displays(
>  {
>  	uint32_t active_disp = 1;
>  
> -	if (bios->regs->BIOS_SCRATCH_3) /*follow up with other asic, todo*/
> -		active_disp = REG_READ(BIOS_SCRATCH_3) & 0XFFFF;
> +	active_disp = REG_READ(BIOS_SCRATCH_3) & 0XFFFF;

So why is the if statement removed?

>  	return active_disp;
>  }

[…]


Kind regards,

Paul

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