Merge tag 'media/v5.12-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media

Pull media updates from Mauro Carvalho Chehab:

 - some core fixes in VB2 mem2mem support

 - some improvements and cleanups in V4L2 async kAPI

 - newer controls in V4L2 API for H-264 and HEVC codecs

 - allegro-dvt driver was promoted from staging

 - new i2c sendor drivers: imx334, ov5648, ov8865

 - new automobile camera module: rdacm21

 - ipu3 cio2 driver started gained support for some ACPI BIOSes

 - new ATSC frontend: MaxLinear mxl692 VSB tuner/demod

 - the SMIA/CCS driver gained more support for CSS standard

 - several driver fixes, updates and improvements

* tag 'media/v5.12-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media: (362 commits)
  media: v4l: async: Fix kerneldoc documentation for async functions
  media: i2c: max9271: Add MODULE_* macros
  media: i2c: Kconfig: Make MAX9271 a module
  media: imx334: 'ret' is uninitialized, should have been PTR_ERR()
  media: i2c: Add imx334 camera sensor driver
  media: dt-bindings: media: Add bindings for imx334
  media: ov8856: Configure sensor for GRBG Bayer for all modes
  media: i2c: imx219: Implement V4L2_CID_LINK_FREQ control
  media: ov5675: fix vflip/hflip control
  media: ipu3-cio2: Build bridge only if ACPI is enabled
  media: Remove the legacy v4l2-clk API
  media: ov6650: Use the generic clock framework
  media: mt9m111: Use the generic clock framework
  media: ov9640: Use the generic clock framework
  media: pxa_camera: Drop the v4l2-clk clock register
  media: mach-pxa: Register the camera sensor fixed-rate clock
  media: i2c: imx258: get clock from device properties and enable it via runtime PM
  media: i2c: imx258: simplify getting state container
  media: i2c: imx258: add support for binding via device tree
  media: dt-bindings: media: imx258: add bindings for IMX258 sensor
  ...

1 files changed, 12 insertions, 3 deletions

diff --git a/drivers/media/v4l2-core/v4l2-mem2mem.c b/drivers/media/v4l2-core/v4l2-mem2mem.c
index b221b4e438a1..e7f4bf5bc8dd 100644
--- a/drivers/media/v4l2-core/v4l2-mem2mem.c
+++ b/drivers/media/v4l2-core/v4l2-mem2mem.c
@@ -887,9 +887,6 @@ static __poll_t v4l2_m2m_poll_for_data(struct file *file,
 	src_q = v4l2_m2m_get_src_vq(m2m_ctx);
 	dst_q = v4l2_m2m_get_dst_vq(m2m_ctx);
 
-	poll_wait(file, &src_q->done_wq, wait);
-	poll_wait(file, &dst_q->done_wq, wait);
-
 	/*
 	 * There has to be at least one buffer queued on each queued_list, which
 	 * means either in driver already or waiting for driver to claim it
@@ -922,9 +919,21 @@ __poll_t v4l2_m2m_poll(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
 		       struct poll_table_struct *wait)
 {
 	struct video_device *vfd = video_devdata(file);
+	struct vb2_queue *src_q = v4l2_m2m_get_src_vq(m2m_ctx);
+	struct vb2_queue *dst_q = v4l2_m2m_get_dst_vq(m2m_ctx);
 	__poll_t req_events = poll_requested_events(wait);
 	__poll_t rc = 0;
 
+	/*
+	 * poll_wait() MUST be called on the first invocation on all the
+	 * potential queues of interest, even if we are not interested in their
+	 * events during this first call. Failure to do so will result in
+	 * queue's events to be ignored because the poll_table won't be capable
+	 * of adding new wait queues thereafter.
+	 */
+	poll_wait(file, &src_q->done_wq, wait);
+	poll_wait(file, &dst_q->done_wq, wait);
+
 	if (req_events & (EPOLLOUT | EPOLLWRNORM | EPOLLIN | EPOLLRDNORM))
 		rc = v4l2_m2m_poll_for_data(file, m2m_ctx, wait);