Re: [PATCH v2] drm/i915: Increase LSPCON timeout

["Sharma, Shashank" <shashank.sharma@intel.com>]

On 8/18/2018 1:37 AM, Fredrik Schön wrote:

> 100 ms is not enough time for the LSPCON adapter on Intel NUC devices to
> settle. This causes dropped display modes at boot or screen reconfiguration.
> Empirical testing can reproduce the error up to a timeout of 190 ms. Basic
> boot and stress testing at 200 ms has not (yet) failed.
>
> Increase timeout to 400 ms to get some margin of error.
>
> Changes from v1:
> The initial suggestion of 1000 ms was lowered due to concerns about delaying
> valid timeout cases.
> Update patch metadata.
>
> Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=107503
> Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=1570392
> Fixes: 357c0ae9198a ("drm/i915/lspcon: Wait for expected LSPCON mode to settle")
> Cc: Shashank Sharma <shashank.sharma@intel.com>
> Cc: Imre Deak <imre.deak@intel.com>
> Cc: Jani Nikula <jani.nikula@intel.com>
> Cc: <stable@vger.kernel.org> # v4.11+
> Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
> Signed-off-by: Fredrik Schön <fredrik.schon@gmail.com>
> ---
>   drivers/gpu/drm/i915/intel_lspcon.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/i915/intel_lspcon.c b/drivers/gpu/drm/i915/intel_lspcon.c
> index 8ae8f42f430a..6b6758419fb3 100644
> --- a/drivers/gpu/drm/i915/intel_lspcon.c
> +++ b/drivers/gpu/drm/i915/intel_lspcon.c
> @@ -74,7 +74,7 @@ static enum drm_lspcon_mode lspcon_wait_mode(struct intel_lspcon *lspcon,
>   	DRM_DEBUG_KMS("Waiting for LSPCON mode %s to settle\n",
>   		      lspcon_mode_name(mode));
>   
> -	wait_for((current_mode = lspcon_get_current_mode(lspcon)) == mode, 100);
> +	wait_for((current_mode = lspcon_get_current_mode(lspcon)) == mode, 400);
>   	if (current_mode != mode)
>   		DRM_ERROR("LSPCON mode hasn't settled\n");
>   
Looks good to me
Reviewed-by: Shashank Sharma <shashank.sharma@intel.com>

- Shashank