Re: [PATCH v2] staging: rts5208: Replace instances of udelay by usleep_range

From: Alison Schofield
Date: Tue Oct 18 2022 - 13:26:09 EST


On Tue, Oct 18, 2022 at 04:04:02PM +0000, Tanjuate Brunostar wrote:
> Replace the use of udelay by usleep_range as suggested by checkpatch:
>
> CHECK: usleep_range is preferred over udelay; see Documentation/timers/timers-howto.rst
> + udelay(30);
>
> CHECK: usleep_range is preferred over udelay; see Documentation/timers/timers-howto.rst
> + udelay(50);
>

Hi Tanjuate,

I'd expect the commit log here to tell me why this is preferable, and
why this is safe to do - basically your summary of what you found
when you considered the checkpatch error report and then read
timers-howto.rst. Including that this was found my Checkpatch is
good, but that's basically a footnote to the log message, not the
main point.

Having said all that, I see GregKH response and that is typical
for this change. This type of change, needs to be actually tested,
so it's not a good cleanup unless you have the device or some other
convincing proof that what you are doing is safe.

Outreachy advice: when you see a checkpatch error, and are
wondering how its fix will be received, search the Outreachy
mail archive for it. This one, I find repeated instances of
the change being NAK'd because the submitter cannot test it.

Alison

> Signed-off-by: Tanjuate Brunostar <tanjubrunostar0@xxxxxxxxx>
> ---
>
> v2: changed the max values of the usleep_rage instances as they cannot
> be equal to the min values as suggested by checkpatch
>
> drivers/staging/rts5208/ms.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/staging/rts5208/ms.c b/drivers/staging/rts5208/ms.c
> index 14449f8afad5..a9724ca5eccf 100644
> --- a/drivers/staging/rts5208/ms.c
> +++ b/drivers/staging/rts5208/ms.c
> @@ -3235,7 +3235,7 @@ static int ms_write_multiple_pages(struct rtsx_chip *chip, u16 old_blk,
> return STATUS_FAIL;
> }
>
> - udelay(30);
> + usleep_range(30, 31);
>
> rtsx_init_cmd(chip);
>
> @@ -4157,7 +4157,7 @@ int mg_set_ICV(struct scsi_cmnd *srb, struct rtsx_chip *chip)
>
> #ifdef MG_SET_ICV_SLOW
> for (i = 0; i < 2; i++) {
> - udelay(50);
> + usleep_range(50, 51);
>
> rtsx_init_cmd(chip);
>
> --
> 2.34.1
>
>