Re: [PATCH 2/4] drm: ti-sn65dsi86: Check bridge connection failure

[Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>]

On 19/06/2024 22:32, Laurent Pinchart wrote:
> Hi Jacopo,
> 
> Thank you for the patch.
> 
> On Wed, Jun 19, 2024 at 12:22:16PM +0200, Jacopo Mondi wrote:
>> From: Phong Hoang <phong.hoang.wz@renesas.com>
>>
>> Add a check to the register access function when attaching a bridge
>> device.

I think the desc is missing the "why". I'm guessing it's the first 
register access to the IC, and thus verifies that it is accessible.

  Tomi

>>
>> Signed-off-by: Phong Hoang <phong.hoang.wz@renesas.com>
>> Signed-off-by: Jacopo Mondi <jacopo.mondi@ideasonboard.com>
> 
> Reviewed-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
> 
>> ---
>>   drivers/gpu/drm/bridge/ti-sn65dsi86.c | 6 +++++-
>>   1 file changed, 5 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/gpu/drm/bridge/ti-sn65dsi86.c b/drivers/gpu/drm/bridge/ti-sn65dsi86.c
>> index 84698a0b27a8..b7df53577987 100644
>> --- a/drivers/gpu/drm/bridge/ti-sn65dsi86.c
>> +++ b/drivers/gpu/drm/bridge/ti-sn65dsi86.c
>> @@ -696,6 +696,7 @@ static struct ti_sn65dsi86 *bridge_to_ti_sn65dsi86(struct drm_bridge *bridge)
>>   
>>   static int ti_sn_attach_host(struct auxiliary_device *adev, struct ti_sn65dsi86 *pdata)
>>   {
>> +	int ret;
>>   	int val;
>>   	struct mipi_dsi_host *host;
>>   	struct mipi_dsi_device *dsi;
>> @@ -720,8 +721,11 @@ static int ti_sn_attach_host(struct auxiliary_device *adev, struct ti_sn65dsi86
>>   
>>   	/* check if continuous dsi clock is required or not */
>>   	pm_runtime_get_sync(dev);
>> -	regmap_read(pdata->regmap, SN_DPPLL_SRC_REG, &val);
>> +	ret = regmap_read(pdata->regmap, SN_DPPLL_SRC_REG, &val);
>>   	pm_runtime_put_autosuspend(dev);
>> +	if (ret)
>> +		return ret;
>> +
>>   	if (!(val & DPPLL_CLK_SRC_DSICLK))
>>   		dsi->mode_flags |= MIPI_DSI_CLOCK_NON_CONTINUOUS;
>>   
>