[PATCH v2 2/2] drm: adv7511: Fix out-of-bounds array in clock_div_by_lanes

[Laurent Pinchart]

Hi Biju,

Thank you for the patch.

On Tue, Nov 05, 2024 at 11:12:19AM +0000, Biju Das wrote:
> Fix out-of-bounds array in adv7511_dsi_config_timing_gen(),
> when dsi lanes = 1.

Does the hardware support using the internal timing generator with a
single lane ? If so adv7511_dsi_config_timing_gen() should be fixed,
otherwise that should be explained in the commit message, and mentioned
with a comment in adv7533_parse_dt(). I would also print an error
message in that case.

If the internal timing generator can't be used with a single lane, the
DT bindings should also be updated to document that.

> Fixes: 78fa479d703c ("drm/bridge: adv7533: Use internal timing generator")
> Reported-by: Hien Huynh <hien.huynh.px at renesas.com>
> Signed-off-by: Biju Das <biju.das.jz at bp.renesas.com>
> ---
> Changes in v2:
>  - Added the tag "Cc: stable at vger.kernel.org" in the sign-off area.
>  - Dropped Archit Taneja invalid Mail address
> ---
>  drivers/gpu/drm/bridge/adv7511/adv7533.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/drivers/gpu/drm/bridge/adv7511/adv7533.c b/drivers/gpu/drm/bridge/adv7511/adv7533.c
> index 3e57ba838e5e..0c2236e53af5 100644
> --- a/drivers/gpu/drm/bridge/adv7511/adv7533.c
> +++ b/drivers/gpu/drm/bridge/adv7511/adv7533.c
> @@ -185,6 +185,9 @@ int adv7533_parse_dt(struct device_node *np, struct adv7511 *adv)
>  	adv->use_timing_gen = !of_property_read_bool(np,
>  						"adi,disable-timing-generator");
>  
> +	if (adv->use_timing_gen && num_lanes == 1)
> +		return -EINVAL;
> +
>  	/* TODO: Check if these need to be parsed by DT or not */
>  	adv->rgb = true;
>  	adv->embedded_sync = false;

-- 
Regards,

Laurent Pinchart