4bb7267dc4
When a fatal error occurs that render the device unusable, the only options for a driver to signal the error condition to userspace is to set the V4L2_BUF_FLAG_ERROR flag when dequeuing buffers and to return an error from the buffer prepare handler when queuing buffers. The buffer error flag indicates a transient error and can't be used by applications to detect fatal errors. Returning an error from vb2_qbuf() is thus the only real indication that a fatal error occurred. However, this is difficult to handle for multithreaded applications that requeue buffers from a thread other than the control thread. In particular the poll() call in the control thread will not notify userspace of the error. This patch adds an explicit mechanism to report fatal errors to userspace. Drivers can call the vb2_queue_error() function to signal a fatal error. From this moment on, buffer preparation will return -EIO to userspace, and vb2_poll() will set the POLLERR flag and return immediately. The error flag is cleared when cancelling the queue, either at stream off time (through vb2_streamoff) or when releasing the queue with vb2_queue_release(). Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Acked-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com> |
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| .. | ||
| acpi | ||
| asm-generic | ||
| clocksource | ||
| crypto | ||
| drm | ||
| dt-bindings | ||
| keys | ||
| kvm | ||
| linux | ||
| math-emu | ||
| media | ||
| memory | ||
| misc | ||
| net | ||
| pcmcia | ||
| ras | ||
| rdma | ||
| rxrpc | ||
| scsi | ||
| sound | ||
| target | ||
| trace | ||
| uapi | ||
| video | ||
| xen | ||
| Kbuild | ||