RE: [PATCH v4 02/11] mtd: cfi_cmdset_0002: Remove chip_ready() from do_write_buffer()

["Tokunori Ikegami" <ikegami_to@xxxxxxxxxxx>]

Hi Boris-san,

Thank you so much for your quick reviewing.
I see and will do that later.

> This patch actually fixes a bug (as reported in the other thread), so
> please add Fixes and Cc-stable tags and explain why it might cause
> an infinite loop in the commit message.

Regards,
Ikegami

> -----Original Message-----
> From: Boris Brezillon [mailto:bbrezillon@xxxxxxxxxx]
> Sent: Tuesday, February 5, 2019 3:06 AM
> To: Tokunori Ikegami
> Cc: Boris Brezillon; Joakim Tjernlund; linux-mtd@xxxxxxxxxxxxxxxxxxx;
> Chris Packham; Fabio Bettoni
> Subject: Re: [PATCH v4 02/11] mtd: cfi_cmdset_0002: Remove chip_ready()
> from do_write_buffer()
> 
> On Tue,  5 Feb 2019 02:35:41 +0900
> Tokunori Ikegami <ikegami_to@xxxxxxxxxxx> wrote:
> 
> > It is enough to use chip_good() only so chip_ready() is not necessary.
> > Since chip_good() is doing the same check chip_ready() is doing plus an
> extra
> > check to make sure we end up with the data we wrote.
> >
> > For this change the order to check timeout also will be changed at same
> time.
> > The order is not a hard requirement, it's just better to avoid the case
> where
> > the data update happens just after the timeout has expired.
> >
> > Signed-off-by: Tokunori Ikegami <ikegami_to@xxxxxxxxxxx>
> 
> This patch actually fixes a bug (as reported in the other thread), so
> please add Fixes and Cc-stable tags and explain why it might cause
> an infinite loop in the commit message.
> 
> > Cc: Fabio Bettoni <fbettoni@xxxxxxxxx>
> > Co: Hauke Mehrtens <hauke@xxxxxxxxxx>
> > Co: Koen Vandeputte <koen.vandeputte@xxxxxxxxxxxx>
> > Cc: Chris Packham <chris.packham@xxxxxxxxxxxxxxxxxxx>
> > Cc: Joakim Tjernlund <Joakim.Tjernlund@xxxxxxxxxxxx>
> > Cc: Boris Brezillon <boris.brezillon@xxxxxxxxxxxxxxxxxx>
> > Cc: linux-mtd@xxxxxxxxxxxxxxxxxxx
> > ---
> > Changes since v3:
> > - Update the commit message for the comment.
> > - Change the email address of Tokunori Ikegami to
ikegami_to@xxxxxxxxxxx.
> >
> > Changes since v2:
> > - None.
> >
> > Changes since v1:
> > - None.
> >
> >  drivers/mtd/chips/cfi_cmdset_0002.c | 6 +++---
> >  1 file changed, 3 insertions(+), 3 deletions(-)
> >
> > diff --git a/drivers/mtd/chips/cfi_cmdset_0002.c
> b/drivers/mtd/chips/cfi_cmdset_0002.c
> > index 91a491b..ca9d5fa 100755
> > --- a/drivers/mtd/chips/cfi_cmdset_0002.c
> > +++ b/drivers/mtd/chips/cfi_cmdset_0002.c
> > @@ -1878,14 +1878,14 @@ static int __xipram do_write_buffer(struct
> map_info *map, struct flchip *chip,
> >  			continue;
> >  		}
> >
> > -		if (time_after(jiffies, timeo) && !chip_ready(map, adr))
> > -			break;
> > -
> >  		if (chip_good(map, adr, datum)) {
> >  			xip_enable(map, chip, adr);
> >  			goto op_done;
> >  		}
> >
> > +		if (time_after(jiffies, timeo))
> > +			break;
> > +
> >  		/* Latency issues. Drop the lock, wait a while and retry
> */
> >  		UDELAY(map, chip, adr, 1);
> >  	}


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