[PATCH v4 0/2] Clean up min_buffers_needed misusages

[Benjamin Gaignard]

This series implement Hans's RFC: https://www.spinics.net/lists/linux-media/msg244455.html

To summarize Hans's proposal it is needed to distinguish two cases:
- the minimal number of buffers to be allocated when calling
  VIDIOC_REQBUFS.
- the minimale number of queued buffers before start streaming.
Until now drivers use vb2_queue min_buffers_needed field in the both
cases but before introduce delete buffers we need to clarify for which
usage each of them use min_buffers_needed field.

The branch with all patches is here:
https://gitlab.collabora.com/benjamin.gaignard/for-upstream/-/commits/clean_min_need_buffers_v5

I have tested with this command line, I haven't notice issues:
./test-media -kmemleak mc

changes in version 5:
- Fix the comments done by Hans:
  Rework comments on videobuf2-core.h
  Add checks in vb2_core_queue_init().
- Patch test-drivers to use min_reqbufs_allocation field.

changes in version 4:
- restore removed lines in zoran and vdec drivers.

changes in version 3:
- Just rename min_buffers_needed into min_queued_buffers everywhere
  without trying to fix the drivers.
- Introduce min_reqbufs_allocation field to be used when calling VIDIOC_REQBUFS.

changes in version 2:
- change min_buffers_needed into min_queues_buffers instead of min_dma_buffers_needed
- patches order
- only one patch to rename min_buffers_needed into min_queues_buffer

Benjamin Gaignard (3):
  videobuf2: core: Rename min_buffers_needed field to vb2_queue
  videobuf2: Add min_reqbufs_allocation field to vb2_queue structure
  media: test-drivers: Set REQBUFS minimum number of buffers

 drivers/input/touchscreen/atmel_mxt_ts.c      |  2 +-
 drivers/input/touchscreen/sur40.c             |  2 +-
 drivers/media/common/saa7146/saa7146_fops.c   |  2 +-
 .../media/common/videobuf2/videobuf2-core.c   | 34 +++++++++++--------
 drivers/media/dvb-core/dvb_vb2.c              |  2 +-
 drivers/media/i2c/video-i2c.c                 |  2 +-
 drivers/media/pci/bt8xx/bttv-driver.c         |  2 +-
 drivers/media/pci/cobalt/cobalt-v4l2.c        |  2 +-
 drivers/media/pci/cx18/cx18-streams.c         |  2 +-
 drivers/media/pci/cx23885/cx23885-417.c       |  2 +-
 drivers/media/pci/cx23885/cx23885-dvb.c       |  2 +-
 drivers/media/pci/cx23885/cx23885-video.c     |  4 +--
 drivers/media/pci/cx25821/cx25821-video.c     |  2 +-
 drivers/media/pci/cx88/cx88-blackbird.c       |  2 +-
 drivers/media/pci/cx88/cx88-dvb.c             |  2 +-
 drivers/media/pci/cx88/cx88-video.c           |  4 +--
 drivers/media/pci/dt3155/dt3155.c             |  2 +-
 drivers/media/pci/intel/ipu3/ipu3-cio2.c      |  2 +-
 drivers/media/pci/mgb4/mgb4_vin.c             |  2 +-
 drivers/media/pci/mgb4/mgb4_vout.c            |  2 +-
 drivers/media/pci/tw5864/tw5864-video.c       |  2 +-
 drivers/media/pci/tw68/tw68-video.c           |  2 +-
 drivers/media/pci/tw686x/tw686x-video.c       |  2 +-
 drivers/media/pci/zoran/zoran_driver.c        |  6 ++--
 drivers/media/platform/amphion/vpu_v4l2.c     |  4 +--
 drivers/media/platform/aspeed/aspeed-video.c  |  2 +-
 drivers/media/platform/atmel/atmel-isi.c      |  2 +-
 .../platform/chips-media/coda/coda-common.c   |  2 +-
 .../platform/microchip/microchip-isc-base.c   |  2 +-
 drivers/media/platform/nuvoton/npcm-video.c   |  2 +-
 drivers/media/platform/nxp/imx7-media-csi.c   |  2 +-
 .../platform/nxp/imx8-isi/imx8-isi-video.c    |  2 +-
 drivers/media/platform/qcom/venus/vdec.c      |  4 +--
 drivers/media/platform/qcom/venus/venc.c      |  4 +--
 .../platform/renesas/rcar-vin/rcar-dma.c      |  2 +-
 drivers/media/platform/renesas/renesas-ceu.c  |  2 +-
 .../platform/renesas/rzg2l-cru/rzg2l-video.c  |  2 +-
 drivers/media/platform/renesas/sh_vou.c       |  2 +-
 .../platform/rockchip/rkisp1/rkisp1-capture.c |  2 +-
 drivers/media/platform/st/sti/hva/hva-v4l2.c  |  4 +--
 drivers/media/platform/st/stm32/stm32-dcmi.c  |  2 +-
 .../st/stm32/stm32-dcmipp/dcmipp-bytecap.c    |  4 +--
 .../platform/sunxi/sun4i-csi/sun4i_dma.c      |  2 +-
 .../sunxi/sun6i-csi/sun6i_csi_capture.c       |  2 +-
 .../media/platform/sunxi/sun8i-di/sun8i-di.c  |  4 +--
 .../sunxi/sun8i-rotate/sun8i_rotate.c         |  4 +--
 .../media/platform/ti/am437x/am437x-vpfe.c    |  2 +-
 drivers/media/platform/ti/cal/cal-video.c     |  2 +-
 .../media/platform/ti/davinci/vpif_capture.c  |  2 +-
 .../media/platform/ti/davinci/vpif_display.c  |  2 +-
 .../platform/ti/j721e-csi2rx/j721e-csi2rx.c   |  2 +-
 drivers/media/platform/ti/omap/omap_vout.c    |  2 +-
 .../media/test-drivers/vimc/vimc-capture.c    |  2 +-
 drivers/media/test-drivers/vivid/vivid-core.c |  4 +--
 drivers/media/usb/cx231xx/cx231xx-417.c       |  2 +-
 drivers/media/usb/cx231xx/cx231xx-video.c     |  4 +--
 drivers/media/usb/dvb-usb/cxusb-analog.c      |  2 +-
 drivers/media/usb/gspca/gspca.c               |  6 ++--
 .../media/deprecated/atmel/atmel-isc-base.c   |  2 +-
 drivers/staging/media/imx/imx-media-capture.c |  2 +-
 drivers/staging/media/ipu3/ipu3-v4l2.c        |  2 +-
 drivers/staging/media/meson/vdec/vdec.c       |  6 ++--
 .../staging/media/starfive/camss/stf-video.c  |  2 +-
 .../media/sunxi/sun6i-isp/sun6i_isp_capture.c |  2 +-
 .../media/sunxi/sun6i-isp/sun6i_isp_params.c  |  2 +-
 drivers/staging/media/tegra-video/vi.c        |  2 +-
 include/media/videobuf2-core.h                | 20 +++++++++--
 samples/v4l/v4l2-pci-skeleton.c               |  2 +-
 68 files changed, 121 insertions(+), 99 deletions(-)

-- 
2.40.1