Re: Re: [PATCH] media: uvcvideo:Create input device for all uvc devices with status endpoints.

From: ccc194101@xxxxxxx
Date: Mon Nov 04 2024 - 20:36:30 EST


hi Mauro:





> It sounds to me that this is an application bug, not a Kernel one.



> What applications have such bug?





??? This is a testing application produced by a third-party company, and the modification is mainly aimed at improving compatibility.



??? And retaining nodes has no harm and is more suitable for application scenarios.









--------------









ccc194101@xxxxxxx









>Em Mon,? 4 Nov 2024 10:39:47 +0800









>chenchangcheng <ccc194101@xxxxxxx> escreveu:









>









>> Some applications need to check if there is an input device on the camera









>> before proceeding to the next step. When there is no input device,









>> the application will report an error.









>









>Nack.









>









>It is not mandatory for V4L2 devices to create input devices.









>









>It sounds to me that this is an application bug, not a Kernel one.









>What applications have such bug?









>









>> Create input device for all uvc devices with status endpoints.









>> and only when bTriggerSupport and bTriggerUsage are one are









>> allowed to report camera button.









>









>Please fix the application instead.









>









>>









>> Fixes: 3bc22dc66a4f ("media: uvcvideo: Only create input devs if hw supports it")









>









>Regards,









>Mauro









>









>> Signed-off-by: chenchangcheng <ccc194101@xxxxxxx>









>> ---









>>? drivers/media/usb/uvc/uvc_status.c | 13 ++++++-------









>>? 1 file changed, 6 insertions(+), 7 deletions(-)









>>









>> diff --git a/drivers/media/usb/uvc/uvc_status.c b/drivers/media/usb/uvc/uvc_status.c









>> index a78a88c710e2..177640c6a813 100644









>> --- a/drivers/media/usb/uvc/uvc_status.c









>> +++ b/drivers/media/usb/uvc/uvc_status.c









>> @@ -44,9 +44,6 @@ static int uvc_input_init(struct uvc_device *dev)









>>? struct input_dev *input;









>>? int ret;









>>?









>> - if (!uvc_input_has_button(dev))









>> - return 0;









>> -









>









>









>>? input = input_allocate_device();









>>? if (input == NULL)









>>? return -ENOMEM;









>> @@ -110,10 +107,12 @@ static void uvc_event_streaming(struct uvc_device *dev,









>>? if (len <= offsetof(struct uvc_status, streaming))









>>? return;









>>?









>> - uvc_dbg(dev, STATUS, "Button (intf %u) %s len %d\n",









>> - status->bOriginator,









>> - status->streaming.button ? "pressed" : "released", len);









>> - uvc_input_report_key(dev, KEY_CAMERA, status->streaming.button);









>> + if (uvc_input_has_button(dev)) {









>> + uvc_dbg(dev, STATUS, "Button (intf %u) %s len %d\n",









>> + status->bOriginator,









>> + status->streaming.button ? "pressed" : "released", len);









>> + uvc_input_report_key(dev, KEY_CAMERA, status->streaming.button);









>> + }









>>? } else {









>>? uvc_dbg(dev, STATUS, "Stream %u error event %02x len %d\n",









>>? status->bOriginator, status->bEvent, len);









>









>









>









>Thanks,









>Mauro