Re: [PATCH 4.16 41/72] mtd: rawnand: Make sure we wait tWB before polling the STATUS reg

[Geert Uytterhoeven]

On Mon, May 14, 2018 at 11:09 AM, Boris Brezillon
<boris.brezillon@xxxxxxxxxxx> wrote:
> On Mon, 14 May 2018 11:04:22 +0200
> Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> wrote:
>
>> On Mon, May 14, 2018 at 09:32:51AM +0200, Geert Uytterhoeven wrote:
>> > On Mon, May 14, 2018 at 8:48 AM, Greg Kroah-Hartman
>> > <gregkh@xxxxxxxxxxxxxxxxxxx> wrote:
>> > > 4.16-stable review patch.  If anyone has any objections, please let me know.
>> > >
>> > > ------------------
>> > >
>> > > From: Boris Brezillon <boris.brezillon@xxxxxxxxxxx>
>> > >
>> > > commit 3057fcef385348fe85173f1b0c824d89f1176f72 upstream.
>> > >
>> > > NAND chips require a bit of time to take the NAND operation into
>> > > account and set the BUSY bit in the STATUS reg. Make sure we don't poll
>> > > the STATUS reg too early in nand_soft_waitrdy().
>> > >
>> > > Fixes: 8878b126df76 ("mtd: nand: add ->exec_op() implementation")
>> > > Cc: <stable@xxxxxxxxxxxxxxx>
>> > > Signed-off-by: Boris Brezillon <boris.brezillon@xxxxxxxxxxx>
>> > > Acked-by: Miquel Raynal <miquel.raynal@xxxxxxxxxxx>
>> > > Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
>> > >
>> > > ---
>> > >  drivers/mtd/nand/nand_base.c |    5 +++++
>> > >  1 file changed, 5 insertions(+)
>> > >
>> > > --- a/drivers/mtd/nand/nand_base.c
>> > > +++ b/drivers/mtd/nand/nand_base.c
>> > > @@ -707,12 +707,17 @@ static void nand_wait_status_ready(struc
>> > >   */
>> > >  int nand_soft_waitrdy(struct nand_chip *chip, unsigned long timeout_ms)
>> > >  {
>> > > +       const struct nand_sdr_timings *timings;
>> > >         u8 status = 0;
>> > >         int ret;
>> > >
>> > >         if (!chip->exec_op)
>> > >                 return -ENOTSUPP;
>> > >
>> > > +       /* Wait tWB before polling the STATUS reg. */
>> > > +       timings = nand_get_sdr_timings(&chip->data_interface);
>> > > +       ndelay(PSEC_TO_NSEC(timings->tWB_max));
>> > > +
>> > >         ret = nand_status_op(chip, NULL);
>> > >         if (ret)
>> > >                 return ret;
>> > >
>> > >
>> >
>> >
>> > kbuild test robot via vger.kernel.org
>> > Attachments1:36 PM (19 hours ago)
>> > to Boris, kbuild-all, linux-kernel
>> > tree:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
>> > master
>> > head:   ccda3c4b77777f66aeb3c531352bb40d59501c59
>> > commit: 3057fcef385348fe85173f1b0c824d89f1176f72 mtd: rawnand: Make
>> > sure we wait tWB before polling the STATUS reg
>> > date:   3 days ago
>> > config: m68k-allyesconfig (attached as .config)
>> > compiler: m68k-linux-gnu-gcc (Debian 7.2.0-11) 7.2.0
>> > reproduce:
>> >         wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross
>> > -O ~/bin/make.cross
>> >         chmod +x ~/bin/make.cross
>> >         git checkout 3057fcef385348fe85173f1b0c824d89f1176f72
>> >         # save the attached .config to linux build tree
>> >         make.cross ARCH=m68k
>> >
>> > All errors (new ones prefixed by >>):
>> >
>> >    drivers/mtd/nand/raw/nand_base.o: In function `nand_soft_waitrdy':
>> > >> nand_base.c:(.text+0x1022): undefined reference to `__udivdi3'
>>
>> Ugh.  Does this also happen in Linus's tree?
>
> Yes it does, unfortunately :-/. I posted a fix here [1].
>
> [1]https://patchwork.kernel.org/patch/10396217/

And a fix for the root cause:
https://patchwork.kernel.org/patch/10397919/

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds