On 06/08/2025 11:48, Laurent Pinchart wrote:
> Hi Hans,
>
> On Wed, Aug 06, 2025 at 10:16:37AM +0200, Hans Verkuil wrote:
>> On 02/08/2025 11:22, Jacopo Mondi wrote:
>>> From: Laurent Pinchart <laurent.pinch...@ideasonboard.com>
>>>
>>> Accessing file->private_data manually to retrieve the v4l2_fh pointer is
>>> error-prone, as the field is a void * and will happily cast implicitly
>>> to any pointer type.
>>>
>>> Replace all remaining locations that read the v4l2_fh pointer directly
>>> from file->private_data and cast it to driver-specific file handle
>>> structures with driver-specific functions that use file_to_v4l2_fh() and
>>> perform the same cast.
>>>
>>> No functional change is intended, this only paves the way to remove
>>> direct accesses to file->private_data and make V4L2 drivers safer.
>>> Other accesses to the field will be addressed separately.
>>>
>>> Signed-off-by: Laurent Pinchart <laurent.pinch...@ideasonboard.com>
>>> Signed-off-by: Jacopo Mondi <jacopo.mo...@ideasonboard.com>
>>> ---
>>> drivers/media/pci/ivtv/ivtv-driver.h | 5 ++++
>>> drivers/media/pci/ivtv/ivtv-fileops.c | 10 +++----
>>> drivers/media/pci/ivtv/ivtv-ioctl.c | 8 +++---
>>> drivers/media/platform/allegro-dvt/allegro-core.c | 7 ++++-
>>> drivers/media/platform/amlogic/meson-ge2d/ge2d.c | 8 ++++--
>>> .../media/platform/chips-media/coda/coda-common.c | 7 ++++-
>>> .../platform/chips-media/wave5/wave5-helper.c | 2 +-
>>> .../media/platform/chips-media/wave5/wave5-vpu.h | 5 ++++
>>> drivers/media/platform/m2m-deinterlace.c | 7 ++++-
>>> .../media/platform/mediatek/jpeg/mtk_jpeg_core.c | 7 ++++-
>>> drivers/media/platform/mediatek/mdp/mtk_mdp_m2m.c | 7 ++++-
>>> .../media/platform/mediatek/mdp3/mtk-mdp3-m2m.c | 7 ++++-
>>> .../mediatek/vcodec/decoder/mtk_vcodec_dec_drv.c | 2 +-
>>> .../mediatek/vcodec/decoder/mtk_vcodec_dec_drv.h | 5 ++++
>>> .../mediatek/vcodec/encoder/mtk_vcodec_enc_drv.c | 2 +-
>>> .../mediatek/vcodec/encoder/mtk_vcodec_enc_drv.h | 5 ++++
>>> drivers/media/platform/nxp/imx-jpeg/mxc-jpeg.c | 7 ++++-
>>> drivers/media/platform/nxp/imx8-isi/imx8-isi-m2m.c | 7 ++++-
>>> drivers/media/platform/nxp/mx2_emmaprp.c | 7 ++++-
>>> drivers/media/platform/renesas/rcar_fdp1.c | 7 ++++-
>>> drivers/media/platform/renesas/rcar_jpu.c | 7 ++++-
>>> drivers/media/platform/rockchip/rga/rga.c | 3 +--
>>> drivers/media/platform/rockchip/rga/rga.h | 5 ++++
>>> drivers/media/platform/rockchip/rkvdec/rkvdec.c | 2 +-
>>> drivers/media/platform/rockchip/rkvdec/rkvdec.h | 5 ++++
>>> .../media/platform/samsung/exynos-gsc/gsc-core.h | 6 +++++
>>> .../media/platform/samsung/exynos-gsc/gsc-m2m.c | 6 ++---
>>> .../media/platform/samsung/exynos4-is/fimc-core.h | 5 ++++
>>> .../media/platform/samsung/exynos4-is/fimc-m2m.c | 2 +-
>>> drivers/media/platform/samsung/s5p-g2d/g2d.c | 7 +++--
>>> .../media/platform/samsung/s5p-jpeg/jpeg-core.c | 9 +++++--
>>> drivers/media/platform/samsung/s5p-mfc/s5p_mfc.c | 6 ++---
>>> .../platform/samsung/s5p-mfc/s5p_mfc_common.h | 6 +++++
>>> drivers/media/platform/st/sti/bdisp/bdisp-v4l2.c | 7 ++++-
>>> drivers/media/platform/st/sti/delta/delta-v4l2.c | 26 +++++++++++-------
>>> drivers/media/platform/st/sti/hva/hva-v4l2.c | 31
>>> ++++++++++++----------
>>> drivers/media/platform/st/sti/hva/hva.h | 2 --
>>> drivers/media/platform/st/stm32/dma2d/dma2d.c | 7 +++--
>>> drivers/media/platform/sunxi/sun8i-di/sun8i-di.c | 3 +--
>>> .../platform/sunxi/sun8i-rotate/sun8i_rotate.c | 3 +--
>>> drivers/media/platform/ti/omap3isp/ispvideo.c | 4 +--
>>> drivers/media/platform/ti/omap3isp/ispvideo.h | 6 +++++
>>> drivers/media/platform/verisilicon/hantro.h | 5 ++++
>>> drivers/media/platform/verisilicon/hantro_drv.c | 3 +--
>>> drivers/staging/media/imx/imx-media-csc-scaler.c | 7 ++++-
>>> drivers/staging/media/meson/vdec/vdec.c | 24 ++++++-----------
>>> drivers/staging/media/meson/vdec/vdec.h | 5 ++++
>>> drivers/staging/media/sunxi/cedrus/cedrus.c | 3 +--
>>> drivers/staging/media/sunxi/cedrus/cedrus.h | 5 ++++
>>> drivers/staging/media/sunxi/cedrus/cedrus_video.c | 5 ----
>>> 50 files changed, 237 insertions(+), 100 deletions(-)
>>>
>>> diff --git a/drivers/media/pci/ivtv/ivtv-driver.h
>>> b/drivers/media/pci/ivtv/ivtv-driver.h
>>> index
>>> a6ffa99e16bc64a5b7d3e48c1ab32b49a7989242..cad548b28e360ecfe2bcb9fcb5d12cd8823c3727
>>> 100644
>>> --- a/drivers/media/pci/ivtv/ivtv-driver.h
>>> +++ b/drivers/media/pci/ivtv/ivtv-driver.h
>>> @@ -388,6 +388,11 @@ static inline struct ivtv_open_id *fh2id(struct
>>> v4l2_fh *fh)
>>> return container_of(fh, struct ivtv_open_id, fh);
>>> }
>>>
>>> +static inline struct ivtv_open_id *file2id(struct file *filp)
>>> +{
>>> + return container_of(file_to_v4l2_fh(filp), struct ivtv_open_id, fh);
>>
>> Why not write:
>>
>> return fh2id(file_to_v4l2_fh(filp));
>>
>> Same for all other drivers that do this. I prefer to have the contained_of()
>> in just one place.
>
> Because fh2id gets removed in "[PATCH 57/65] media: ivtv: Access v4l2_fh
> from file". I can use it in this patch and drop it later, would you
> prefer that ?
Based on the irc discussion some drivers need both, so yes, I prefer that the
file2foo inline calls the fh2foo inline.
Regards,
Hans
>
>>> +}
>>> +
>>> struct yuv_frame_info
>>> {
>>> u32 update;
>>
>> <snip>
>>
>>> diff --git a/drivers/media/platform/allegro-dvt/allegro-core.c
>>> b/drivers/media/platform/allegro-dvt/allegro-core.c
>>> index
>>> 1f134e08923a528cc676f825da68951c97ac2f25..74977f3ae4844022c04de877f31b4fc6aaac0749
>>> 100644
>>> --- a/drivers/media/platform/allegro-dvt/allegro-core.c
>>> +++ b/drivers/media/platform/allegro-dvt/allegro-core.c
>>> @@ -302,6 +302,11 @@ struct allegro_channel {
>>> unsigned int error;
>>> };
>>>
>>> +static inline struct allegro_channel *file_to_channel(struct file *filp)
>>> +{
>>> + return container_of(file_to_v4l2_fh(filp), struct allegro_channel, fh);
>>> +}
>>> +
>>> static inline int
>>> allegro_channel_get_i_frame_qp(struct allegro_channel *channel)
>>> {
>>> @@ -3229,7 +3234,7 @@ static int allegro_open(struct file *file)
>>>
>>> static int allegro_release(struct file *file)
>>> {
>>> - struct allegro_channel *channel = fh_to_channel(file->private_data);
>>> + struct allegro_channel *channel = file_to_channel(file);
>>
>> So a file_to_channel inline function was added, but it is used in just one
>> place.
>>
>> I would prefer to just drop the inline function and instead write:
>>
>> struct allegro_channel *channel = fh_to_channel(file_to_v4l2_fh(file));
>>
>> If this is needed in two or more places, then the extra inline makes sense,
>> but it is a fairly common pattern that it is only needed in the release
>> function.
>>
>> Adding a new inline just for that seems overkill to me.
>
> file_to_channel() gets used in more places in "[PATCH 29/65] media:
> allegro: Access v4l2_fh from file", where fh_to_channel() is dropped.
> I'd rather keep it in this patch instead of having to modify the
> allegro_release() function in patch 29/65.
>
>>>
>>> v4l2_m2m_ctx_release(channel->fh.m2m_ctx);
>>>
>
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