Hi Jiasheng,
Thank you for the patch.
On Wed, Jun 01, 2022 at 10:48:22AM +0800, Jiasheng Jiang wrote:
> As mipi_dsi_driver_register could return error if fails,
> it should be better to check the return value and return error
> if fails.
>
> Fixes: 1e4d58cd7f88 ("drm/bridge: adv7533: Create a MIPI DSI device")
> Signed-off-by: Jiasheng Jiang <[email protected]>
> ---
> drivers/gpu/drm/bridge/adv7511/adv7511_drv.c | 9 +++++++--
> 1 file changed, 7 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c b/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c
> index 5bb9300040dd..795855b41eb2 100644
> --- a/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c
> +++ b/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c
> @@ -1392,8 +1392,13 @@ static struct i2c_driver adv7511_driver = {
>
> static int __init adv7511_init(void)
> {
> - if (IS_ENABLED(CONFIG_DRM_MIPI_DSI))
> - mipi_dsi_driver_register(&adv7533_dsi_driver);
> + int ret;
> +
> + if (IS_ENABLED(CONFIG_DRM_MIPI_DSI)) {
> + ret = mipi_dsi_driver_register(&adv7533_dsi_driver);
> + if (ret)
> + return ret;
> + }
>
> return i2c_add_driver(&adv7511_driver);
While at it, should this then call mipi_dsi_driver_unregister() on
failure ?
> }
> --
> 2.25.1
>
--
Regards,
Laurent Pinchart
On Wed, Jun 01, 2022 at 05:15:37PM +0800, Laurent Pinchart wrote:
>> Well, as far as I am concerned, the adv7511_exit() in the same file has already dealt with the issue.
>> Therefore, it might not be necessary to add another mipi_dsi_driver_unregister().
>
> The issue is that adv7511_exit() is not called if adv7511_init() fails.
Sorry, I can not find the caller of adv7511_init().
Please give me more detail.
Thanks,
Jiang
On Wed, Jun 01, 2022 at 02:52:00PM +0800, Laurent Pinchart wrote:
>> static int __init adv7511_init(void)
>> {
>> - if (IS_ENABLED(CONFIG_DRM_MIPI_DSI))
>> - mipi_dsi_driver_register(&adv7533_dsi_driver);
>> + int ret;
>> +
>> + if (IS_ENABLED(CONFIG_DRM_MIPI_DSI)) {
>> + ret = mipi_dsi_driver_register(&adv7533_dsi_driver);
>> + if (ret)
>> + return ret;
>> + }
>>
>> return i2c_add_driver(&adv7511_driver);
>
> While at it, should this then call mipi_dsi_driver_unregister() on
> failure ?
Well, as far as I am concerned, the adv7511_exit() in the same file has already dealt with the issue.
Therefore, it might not be necessary to add another mipi_dsi_driver_unregister().
Thanks,
Jiang
On Wed, Jun 01, 2022 at 04:45:01PM +0800, Jiasheng Jiang wrote:
> On Wed, Jun 01, 2022 at 02:52:00PM +0800, Laurent Pinchart wrote:
> >> static int __init adv7511_init(void)
> >> {
> >> - if (IS_ENABLED(CONFIG_DRM_MIPI_DSI))
> >> - mipi_dsi_driver_register(&adv7533_dsi_driver);
> >> + int ret;
> >> +
> >> + if (IS_ENABLED(CONFIG_DRM_MIPI_DSI)) {
> >> + ret = mipi_dsi_driver_register(&adv7533_dsi_driver);
> >> + if (ret)
> >> + return ret;
> >> + }
> >>
> >> return i2c_add_driver(&adv7511_driver);
> >
> > While at it, should this then call mipi_dsi_driver_unregister() on
> > failure ?
>
> Well, as far as I am concerned, the adv7511_exit() in the same file has already dealt with the issue.
> Therefore, it might not be necessary to add another mipi_dsi_driver_unregister().
The issue is that adv7511_exit() is not called if adv7511_init() fails.
--
Regards,
Laurent Pinchart
On Wed, Jun 01, 2022 at 07:12:55PM +0800, Jiasheng Jiang wrote:
> On Wed, Jun 01, 2022 at 05:15:37PM +0800, Laurent Pinchart wrote:
> >> Well, as far as I am concerned, the adv7511_exit() in the same file has already dealt with the issue.
> >> Therefore, it might not be necessary to add another mipi_dsi_driver_unregister().
> >
> > The issue is that adv7511_exit() is not called if adv7511_init() fails.
>
> Sorry, I can not find the caller of adv7511_init().
> Please give me more detail.
It's called by the kernel when the module is unloaded (module_exit).
It's not what Laurent is saying though.
His point is that in adv7511, if i2c_add_driver fails, you'll still need
to call mipi_dsi_driver_unregister to clean things up.
Maxime