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

From: Geert Uytterhoeven <geert@linux-m68k.org>
To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	stable <stable@vger.kernel.org>,
	Boris Brezillon <boris.brezillon@bootlin.com>,
	Miquel Raynal <miquel.raynal@bootlin.com>
Subject: Re: [PATCH 4.16 41/72] mtd: rawnand: Make sure we wait tWB before polling the STATUS reg
Date: Mon, 14 May 2018 11:32:00 +0200	[thread overview]
Message-ID: <CAMuHMdVfFD0zZk+Vpx-SXHQBjfQTMjnLP98-7xNH0GPcmfVwXw@mail.gmail.com> (raw)
In-Reply-To: <20180514090422.GA25724@kroah.com>

Hi Greg,

On Mon, May 14, 2018 at 11:04 AM, Greg Kroah-Hartman
<gregkh@linuxfoundation.org> 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@linuxfoundation.org> wrote:
>> > 4.16-stable review patch.  If anyone has any objections, please let me know.
>> >
>> > ------------------
>> >
>> > From: Boris Brezillon <boris.brezillon@bootlin.com>
>> >
>> > 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@vger.kernel.org>
>> > Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>
>> > Acked-by: Miquel Raynal <miquel.raynal@bootlin.com>
>> > Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
>> >
>> > ---
>> >  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?

Unfortunately yes, this is torvalds/linux.git, cfr. "tree" above.

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

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