On 17.04.2023 11:44, AngeloGioacchino Del Regno wrote:
> Il 17/04/23 11:44, AngeloGioacchino Del Regno ha scritto:
>> Il 17/04/23 09:25, Neil Armstrong ha scritto:
>>> On 15/04/2023 13:00, Konrad Dybcio wrote:
>>>> In a very peculiar case when probing and registering with the secondary
>>>> DSI host succeeds, but the OF backlight or DSI attachment fails, the
>>>> primary DSI device is automatically cleaned up, but the secondary one
>>>> is not, leading to -EEXIST when the driver core tries to handle
>>>> -EPROBE_DEFER.
>>>>
>>>> Unregister the DSI1 device manually on failure to prevent that.
>>>>
>>>> Fixes: 623a3531e9cf ("drm/panel: Add driver for Novatek NT35950 DSI DriverIC panels")
>>>> Signed-off-by: Konrad Dybcio <konrad.dybcio@xxxxxxxxxx>
>>>> ---
>>>> drivers/gpu/drm/panel/panel-novatek-nt35950.c | 8 +++++++-
>>>> 1 file changed, 7 insertions(+), 1 deletion(-)
>>>>
>>>> diff --git a/drivers/gpu/drm/panel/panel-novatek-nt35950.c b/drivers/gpu/drm/panel/panel-novatek-nt35950.c
>>>> index abf752b36a52..7498fc6258bb 100644
>>>> --- a/drivers/gpu/drm/panel/panel-novatek-nt35950.c
>>>> +++ b/drivers/gpu/drm/panel/panel-novatek-nt35950.c
>>>> @@ -585,8 +585,11 @@ static int nt35950_probe(struct mipi_dsi_device *dsi)
>>>> DRM_MODE_CONNECTOR_DSI);
>>>> ret = drm_panel_of_backlight(&nt->panel);
>>>> - if (ret)
>>>> + if (ret) {
>>
>> If this is not a dual-DSI case, nt->dsi[1] will be NULL: I agree it's still
>> fine as in the kernel won't crash in that case, but for logical correctness
>> I would still account for that:
>>
>> if (num_dsis == 2)
>> mipi_dsi_device_unregister(nt->dsi[1]);
>>
>>>> + mipi_dsi_device_unregister(nt->dsi[1]);
>>>> +
>>>> return dev_err_probe(dev, ret, "Failed to get backlight\n");
>>>> + }
>>>> drm_panel_add(&nt->panel);
>>>> @@ -602,6 +605,9 @@ static int nt35950_probe(struct mipi_dsi_device *dsi)
>>>> ret = mipi_dsi_attach(nt->dsi[i]);
>>>> if (ret < 0) {
>>
>> Same here, please add a check for num_dsis.
Right, I'll send an incremental patch to fix the fix, thanks
for spotting this!
Konrad
>>
>> Regards,
>> Angelo
>
> Eh, too late, I just noticed that this got picked already...
