[Intel-gfx] [PATCH] drm/i915: Use 18 fast wake fast wake AUX sync len

[Murthy, Arun R]

> -----Original Message-----
> From: Intel-gfx <intel-gfx-bounces at lists.freedesktop.org> On Behalf Of Jouni
> Högander
> Sent: Monday, May 29, 2023 6:30 PM
> To: intel-gfx at lists.freedesktop.org
> Subject: [Intel-gfx] [PATCH] drm/i915: Use 18 fast wake fast wake AUX sync
> len
> 
> HW default for wake sync pulses is 18. 10 precarge and 8 preamble. There is
> no reason to change this especially as it is causing problems with certain eDP
> panels.
> 
> Signed-off-by: Jouni Högander <jouni.hogander at intel.com>
> Fixes: 605f7c731333 ("drm/i915: Fix fast wake AUX sync len")
> Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/8475
> ---
>  drivers/gpu/drm/i915/display/intel_dp_aux.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/i915/display/intel_dp_aux.c
> b/drivers/gpu/drm/i915/display/intel_dp_aux.c
> index 0c27db8ae4f1..197c6e81db14 100644
> --- a/drivers/gpu/drm/i915/display/intel_dp_aux.c
> +++ b/drivers/gpu/drm/i915/display/intel_dp_aux.c
> @@ -129,7 +129,7 @@ static int intel_dp_aux_sync_len(void)
> 
>  static int intel_dp_aux_fw_sync_len(void)  {
> -	int precharge = 16; /* 10-16 */
> +	int precharge = 10; /* 10-16 */

Is this change required in intel_dp_aux_sync_len() as well?

Thanks and Regards,
Arun R Murthy
--------------------

>  	int preamble = 8;
> 
>  	return precharge + preamble;
> --
> 2.34.1