From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pd0-x22e.google.com ([2607:f8b0:400e:c02::22e]) by bombadil.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1XjFCq-00009g-0e for linux-mtd@lists.infradead.org; Tue, 28 Oct 2014 22:25:36 +0000 Received: by mail-pd0-f174.google.com with SMTP id p10so1624089pdj.33 for ; Tue, 28 Oct 2014 15:25:14 -0700 (PDT) Date: Tue, 28 Oct 2014 15:25:11 -0700 From: Brian Norris To: Andrea Adami Subject: Re: [PATCH] mtd: cfi_cmdset_0001.c: fix resume for LH28F640BF chips Message-ID: <20141028222511.GB23619@ld-irv-0074> References: <1414020181-8855-1-git-send-email-andrea.adami@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1414020181-8855-1-git-send-email-andrea.adami@gmail.com> Cc: Dmitry Eremin-Solenikov , David Woodhouse , Jingoo Han , linux-kernel@vger.kernel.org, Paul Gortmaker , linux-mtd@lists.infradead.org, Christian Riesch List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Thu, Oct 23, 2014 at 01:23:01AM +0200, Andrea Adami wrote: > After '#echo mem > /sys/power/state' some devices can not be properly resumed > because apparently the MTD Partition Configuration Register has been reset > to default thus the rootfs cannot be mounted cleanly on resume. > An example of this can be found in the SA-1100 Developer's Manual at 9.5.3.3 > where the second step of the Sleep Shutdown Sequence is described: > "An internal reset is applied to the SA-1100. All units are reset...". > > As workaround we refresh the PCR value as done initially on chip setup. > > This behavior and the fix are confirmed by our tests done on 2 different Zaurus > collie units with kernel 3.17. > > Signed-off-by: Dmitry Eremin-Solenikov > Signed-off-by: Andrea Adami Who's the author? I have a 'From' header (which becomes the patch author) of Andrea, but the sign-off is Dmitry. If you add a 'From: xxx ' line to the beginning of the email, that can clarify the author, even when the author is not emailing. git-send-email will also handle that for you, if the original git commit has the proper author. > --- > drivers/mtd/chips/cfi_cmdset_0001.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/drivers/mtd/chips/cfi_cmdset_0001.c b/drivers/mtd/chips/cfi_cmdset_0001.c > index a7543ba..59e2355 100644 > --- a/drivers/mtd/chips/cfi_cmdset_0001.c > +++ b/drivers/mtd/chips/cfi_cmdset_0001.c > @@ -2590,6 +2590,8 @@ static void cfi_intelext_resume(struct mtd_info *mtd) > > /* Go to known state. Chip may have been power cycled */ > if (chip->state == FL_PM_SUSPENDED) { > + /* Refresh LH28F640BF Partition Config. Register */ > + fixup_LH28F640BF(mtd); OK, that looks fine. But while we're at it, it seems like any chip which has a boot-time fixup hook in cfi_fixup_table[] should be run at resume time, since those chips may have lost power too. For instance, it looks like fixup_unlock_powerup_lock() would need rerun. I'm not sure if we should do a more invasive patch like that without any testing, though. > map_write(map, CMD(0xFF), cfi->chips[i].start); > chip->oldstate = chip->state = FL_READY; > wake_up(&chip->wq); Brian