Messages in this thread |  | | Date | Sun, 18 Dec 2022 21:11:51 +0800 (GMT+08:00) | From | duoming@zju ... | Subject | Re: [PATCH] Revert "char: pcmcia: cm4000_cs: Replace mdelay with usleep_range in set_protocol" |
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Hello,
On Sun, 18 Dec 2022 12:43:27 +0100 Greg KH wrote:
> On Mon, Nov 28, 2022 at 01:39:15PM +0800, Duoming Zhou wrote: > > This reverts commit be826ada52f1fcabed5b5217c94609ebf5967211. > > > > The function monitor_card() is a timer handler that runs in an > > atomic context, but it calls usleep_range() that can sleep. > > As a result, the sleep-in-atomic-context bugs will happen. > > The process is shown below: > > > > (atomic context) > > monitor_card() > > set_protocol() > > usleep_range() //sleep > > > > The origin commit c1986ee9bea3 ("[PATCH] New Omnikey Cardman > > 4000 driver") works fine. > > > > Fixes: be826ada52f1 ("char: pcmcia: cm4000_cs: Replace mdelay with usleep_range in set_protocol") > > Signed-off-by: Duoming Zhou <duoming@zju.edu.cn> > > --- > > drivers/char/pcmcia/cm4000_cs.c | 4 ++-- > > 1 file changed, 2 insertions(+), 2 deletions(-) > > > > diff --git a/drivers/char/pcmcia/cm4000_cs.c b/drivers/char/pcmcia/cm4000_cs.c > > index adaec8fd4b1..7125f89531f 100644 > > --- a/drivers/char/pcmcia/cm4000_cs.c > > +++ b/drivers/char/pcmcia/cm4000_cs.c > > @@ -529,7 +529,7 @@ static int set_protocol(struct cm4000_dev *dev, struct ptsreq *ptsreq) > > DEBUGP(5, dev, "NumRecBytes is valid\n"); > > break; > > } > > - usleep_range(10000, 11000); > > + mdelay(10); > > } > > if (i == 100) { > > DEBUGP(5, dev, "Timeout waiting for NumRecBytes getting " > > @@ -549,7 +549,7 @@ static int set_protocol(struct cm4000_dev *dev, struct ptsreq *ptsreq) > > } > > break; > > } > > - usleep_range(10000, 11000); > > + mdelay(10); > > Can you add a comment that says "can not sleep as this is atomic > context" for these calls so that this doesn't get changed again in the > future?
Thank you for your reply and suggestions! I will add the comment and re-send this patch.
Best regards, Duoming Zhou
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