Re: [PATCH 04/10] drm/tidss: Move reset to the end of dispc_init()

From: Laurent Pinchart
Date: Wed Nov 01 2023 - 09:57:50 EST


Hi Tomi,

Thank you for the patch.

On Wed, Nov 01, 2023 at 11:17:41AM +0200, Tomi Valkeinen wrote:
> We do a DSS reset in the middle of the dispc_init(). While that happens
> to work now, we should really make sure that e..g the fclk, which is
> acquired only later in the function, is enabled when doing a reset. This
> will be handled in a later patch, but for now, let's move the
> dispc_softreset() call to the end of dispc_init(), which is a sensible
> place for it anyway.
>
> Signed-off-by: Tomi Valkeinen <tomi.valkeinen@xxxxxxxxxxxxxxxx>

Reviewed-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>

But do I understand correctly that the device isn't powered up at this
point ? That seems problematic.

I'm also not sure why we need to reset the device at probe time.

> ---
> drivers/gpu/drm/tidss/tidss_dispc.c | 8 ++++----
> 1 file changed, 4 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/gpu/drm/tidss/tidss_dispc.c b/drivers/gpu/drm/tidss/tidss_dispc.c
> index ad7999434299..9430625e2d62 100644
> --- a/drivers/gpu/drm/tidss/tidss_dispc.c
> +++ b/drivers/gpu/drm/tidss/tidss_dispc.c
> @@ -2777,10 +2777,6 @@ int dispc_init(struct tidss_device *tidss)
> return r;
> }
>
> - /* K2G display controller does not support soft reset */
> - if (feat->subrev != DISPC_K2G)
> - dispc_softreset(dispc);
> -
> for (i = 0; i < dispc->feat->num_vps; i++) {
> u32 gamma_size = dispc->feat->vp_feat.color.gamma_size;
> u32 *gamma_table;
> @@ -2831,5 +2827,9 @@ int dispc_init(struct tidss_device *tidss)
>
> tidss->dispc = dispc;
>
> + /* K2G display controller does not support soft reset */
> + if (feat->subrev != DISPC_K2G)
> + dispc_softreset(dispc);
> +
> return 0;
> }
>

--
Regards,

Laurent Pinchart