-----Original Message----- From: stable-owner@vger.kernel.org [mailto:stable-owner@vger.kernel.org] On Behalf Of Chris Packham Sent: Thursday, October 25, 2018 6:24 AM To: IKEGAMI Tokunori; boris.brezillon@free-electrons.com Cc: Hauke Mehrtens; Koen Vandeputte; Fabio Bettoni; Joakim Tjernlund; linux-mtd@lists.infradead.org; stable@vger.kernel.org Subject: Re: [PATCH v2 01/10] mtd: cfi_cmdset_0002: Change do_write_oneword() to use chip_good()
On 20/10/18 5:55 AM, Tokunori Ikegami wrote:
This is required for OpenWrt Project to result the flash write issue as below patche.
Also the original patch in OpenWRT is below.
So change to use chip_good() instead of chip_ready().
The reason to use chip_good() is that just actually fix the issue. And also in the past I had fixed the erase function also as same way by
the
patch below. https://patchwork.ozlabs.org/patch/922656/ Note: The reason for the patch for erase is same.
In my understanding the chip_ready() is just checked the value twice from flash. So I think that sometimes incorrect value is read twice and it is depended on the flash device behavior but not sure..
So change to use chip_good() instead of chip_ready().
I think much of this is commentary for readers of the mailing list not something that should be in the final commit (i.e. it should be after the '---'). The commit message should really reflect what the problem was and how this change fixes it.
[Ikegami] Yes fixed as so.
I think you've got a better handle on what chip_good() does than I do so I won't attempt to provide a commit message here.
Signed-off-by: Tokunori Ikegami ikegami@allied-telesis.co.jp Signed-off-by: Hauke Mehrtens hauke@hauke-m.de Signed-off-by: Koen Vandeputte koen.vandeputte@ncentric.com Signed-off-by: Fabio Bettoni fbettoni@gmail.com Co-Developed-by: Hauke Mehrtens hauke@hauke-m.de Co-Developed-by: Koen Vandeputte koen.vandeputte@ncentric.com Co-Developed-by: Fabio Bettoni fbettoni@gmail.com Reported-by: Fabio Bettoni fbettoni@gmail.com Cc: Chris Packham chris.packham@alliedtelesis.co.nz Cc: Joakim Tjernlund Joakim.Tjernlund@infinera.com Cc: Boris Brezillon boris.brezillon@free-electrons.com Cc: linux-mtd@lists.infradead.org Cc: stable@vger.kernel.org
Changes since v1:
Just update the commit message.
drivers/mtd/chips/cfi_cmdset_0002.c | 18 ++++++++++++------ 1 file changed, 12 insertions(+), 6 deletions(-)
diff --git a/drivers/mtd/chips/cfi_cmdset_0002.c
b/drivers/mtd/chips/cfi_cmdset_0002.c
index 72428b6bfc47..251c9e1675bd 100644 --- a/drivers/mtd/chips/cfi_cmdset_0002.c +++ b/drivers/mtd/chips/cfi_cmdset_0002.c @@ -1627,31 +1627,37 @@ static int __xipram do_write_oneword(struct
map_info *map, struct flchip *chip,
continue; }
if (time_after(jiffies, timeo) && !chip_ready(map, adr)){
if (chip_good(map, adr, datum))break;if (time_after(jiffies, timeo)){ xip_enable(map, chip, adr); printk(KERN_WARNING "MTD %s(): softwaretimeout\n", __func__);
xip_disable(map, chip, adr);
ret = -EIO; break;
if (chip_ready(map, adr))break;- /* Latency issues. Drop the lock, wait a while and retry
*/
UDELAY(map, chip, adr, 1);}
- /* Did we succeed? */
- if (!chip_good(map, adr, datum)) {
- if (ret) { /* reset on all failures. */ map_write(map, CMD(0xF0), chip->start); /* FIXME - should have reset delay before continuing */
if (++retry_cnt <= MAX_RETRIES)
if (++retry_cnt <= MAX_RETRIES) {ret = 0; goto retry;}ret = -EIO; }
xip_enable(map, chip, adr);
op_done: if (mode == FL_OTP_WRITE) otp_exit(map, chip, adr, map_bankwidth(map));