Re: [PATCH V3] media: stk1160: Fixed high volume of stk1160_dbg messages

From: Greg KH
Date: Sat Nov 25 2023 - 02:48:49 EST


On Sat, Nov 25, 2023 at 01:07:38PM +0530, Ghanshyam Agrawal wrote:
> The function stk1160_dbg gets called too many times, which causes
> the output to get flooded with messages. Since stk1160_dbg uses
> printk, it is now replaced with printk_ratelimited directly.
>
> Suggested-by: Phillip Potter <phil@xxxxxxxxxxxxxxxx>
> Signed-off-by: Ghanshyam Agrawal <ghanshyam1898@xxxxxxxxx>
> ---
> V3:
> Fixed the issue with my patch needing previous versions being applied
> first.
>
> Used printk_ratelimited instead of dev_warn_ratelimited because
> of compiler error "incompatible pointer type".
>
> V2:
> To add KERN_WARNING in printk_ratelimited, and later as per warning by
> the checkpatch script, replaced printk_ratelimited with
> dev_warn_ratelimited.
>
> V1:
> The function stk1160_dbg gets called too many times, which causes
> the output to get flooded with messages. Since stk1160_dbg uses
> printk, it is now replaced with dev_warn_ratelimited.
>
> drivers/media/usb/stk1160/stk1160-video.c | 5 ++---
> 1 file changed, 2 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/media/usb/stk1160/stk1160-video.c b/drivers/media/usb/stk1160/stk1160-video.c
> index 4e966f6bf608..98417fa31d70 100644
> --- a/drivers/media/usb/stk1160/stk1160-video.c
> +++ b/drivers/media/usb/stk1160/stk1160-video.c
> @@ -107,8 +107,7 @@ void stk1160_copy_video(struct stk1160 *dev, u8 *src, int len)
>
> /*
> * TODO: These stk1160_dbg are very spammy!
> - * We should 1) check why we are getting them
> - * and 2) add ratelimit.
> + * We should check why we are getting them.
> *
> * UPDATE: One of the reasons (the only one?) for getting these
> * is incorrect standard (mismatch between expected and configured).
> @@ -151,7 +150,7 @@ void stk1160_copy_video(struct stk1160 *dev, u8 *src, int len)
>
> /* Let the bug hunt begin! sanity checks! */
> if (lencopy < 0) {
> - stk1160_dbg("copy skipped: negative lencopy\n");
> + printk_ratelimited(KERN_WARNING "copy skipped: negative lencopy\n");

You changed a debug message level to a KERN_WARNING level? That feels
like a step backwards.

thanks,

greg k-h