From: Przemyslaw Sobon <psobon@amazon.com>
To: <bbrezillon@kernel.org>, <Joakim.Tjernlund@infinera.com>,
<linux-mtd@lists.infradead.org>,
<chris.packham@alliedtelesis.co.nz>, <fbettoni@gmail.com>,
<ikegami@allied-telesis.co.jp>, <liujian56@huawei.com>
Cc: psobon@amazon.com
Subject: [PATCH] mtd: cfi: Fixed endless loop problem in CFI when value was written but corrupted.
Date: Thu, 7 Feb 2019 23:58:06 +0000 [thread overview]
Message-ID: <20190207235806.GA39580@dev-dsk-psobon-2c-1dd9f399.us-west-2.amazon.com> (raw)
Fixes: dfeae1073583(mtd: cfi_cmdset_0002: Change write buffer to
check correct value)
There was an endless loop in CFI Flash driver when a value was written
incorrectly. In such case chip_ready returns true but chip_good returns
false and we never get out of the loop.
The solution was to break the loop in 2 cases, either device is ready or
device is not ready and timeout elapsed. The correctness of the write is
checked after the loop ended. That way we ensure the loop always ends.
Signed-off-by: Przemyslaw Sobon <psobon@amazon.com>
---
drivers/mtd/chips/cfi_cmdset_0002.c | 11 +++++++----
1 file changed, 7 insertions(+), 4 deletions(-)
diff --git a/drivers/mtd/chips/cfi_cmdset_0002.c b/drivers/mtd/chips/cfi_cmdset_0002.c
index 72428b6bfc47..6cc31d2057e9 100644
--- a/drivers/mtd/chips/cfi_cmdset_0002.c
+++ b/drivers/mtd/chips/cfi_cmdset_0002.c
@@ -1879,15 +1879,18 @@ static int __xipram do_write_buffer(struct map_info *map, struct flchip *chip,
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 (chip_ready(map, adr))
+ break;
/* Latency issues. Drop the lock, wait a while and retry */
UDELAY(map, chip, adr, 1);
}
+ if (chip_good(map, adr, datum)) {
+ xip_enable(map, chip, adr);
+ goto op_done;
+ }
+
/*
* Recovery from write-buffer programming failures requires
* the write-to-buffer-reset sequence. Since the last part
--
2.16.5
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next reply other threads:[~2019-02-07 23:58 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-02-07 23:58 Przemyslaw Sobon [this message]
2019-02-08 15:01 ` [PATCH] mtd: cfi: Fixed endless loop problem in CFI when value was written but corrupted Tokunori Ikegami
2019-02-14 0:39 ` Chris Packham
2019-02-19 8:00 ` Boris Brezillon
2019-02-19 20:02 ` Mark Tomlinson
2019-02-20 8:03 ` Boris Brezillon
2019-02-20 20:50 ` Mark Tomlinson
-- strict thread matches above, loose matches on Subject: below --
2019-01-16 0:32 [PATCH] " Przemyslaw Sobon
2019-01-16 8:33 ` Joakim Tjernlund
2019-01-16 8:50 ` Joakim Tjernlund
2019-01-16 8:54 ` Sobon, Przemyslaw
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