On 5/5/24 8:45 PM, Laurent Pinchart wrote:
> The histogram support mixes _irqsave and _irq, causing the following
> smatch warning:
>
> drivers/media/platform/renesas/vsp1/vsp1_histo.c:153 histo_stop_streaming()
> warn: mixing irqsave and irq
>
> The histo_stop_streaming() calls spin_lock_irqsave() followed by
> wait_event_lock_irq(). The former hints that interrupts may be disabled
> by the caller, while the latter reenables interrupts unconditionally.
> This doesn't cause any real bug, as the function is always called with
> interrupts enabled, but the pattern is still in correct.
Incorrect? :-)
> Fix the problem by using spin_lock_irq() instead of spin_lock_irqsave()
> in histo_stop_streaming(). While at it, switch to spin_lock_irq() and
> spin_lock() as appropriate elsewhere.
>
> Fixes: 99362e32332b ("[media] v4l: vsp1: Add histogram support")
> Reported-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
> Closes: https://lore.kernel.org/linux-renesas-soc/164d74ff-312c-468f-be64-afa7182cd2f4@moroto.mountain/
> Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@xxxxxxxxxxxxxxxx>
> ---
> .../media/platform/renesas/vsp1/vsp1_histo.c | 20 ++++++++-----------
> 1 file changed, 8 insertions(+), 12 deletions(-)
>
> diff --git a/drivers/media/platform/renesas/vsp1/vsp1_histo.c b/drivers/media/platform/renesas/vsp1/vsp1_histo.c
> index 71155282ca11..cd1c8778662e 100644
> --- a/drivers/media/platform/renesas/vsp1/vsp1_histo.c
> +++ b/drivers/media/platform/renesas/vsp1/vsp1_histo.c
[...]
MBR, Sergey
