As reported by the OpenWRT team, write requests sometimes fail on some
platforms.
Currently to check the state chip_ready() is used correctly as described by
the flash memory S29GL256P11TFI01 datasheet.
Also chip_good() is used to check if the write is succeeded and it was
implemented by the commit fb4a90bfcd6d8 ("[MTD] CFI-0002 - Improve error
checking").
But actually the write failure is caused on some platforms and also it can
be fixed by using chip_good() to check the state and retry instead.
Also it seems that it is caused after repeated about 1,000 times to retry
the write one word with the reset command.
By using chip_good() to check the state to be done it can be reduced the
retry with reset.
It is depended on the actual flash chip behavior so the root cause is
unknown.
Signed-off-by: Tokunori Ikegami <ikegami.t(a)gmail.com>
Signed-off-by: Felix Fietkau <nbd(a)nbd.name>
Signed-off-by: Hauke Mehrtens <hauke(a)hauke-m.de>
Reported-by: Fabio Bettoni <fbettoni(a)gmail.com>
Cc: Chris Packham <chris.packham(a)alliedtelesis.co.nz>
Cc: Joakim Tjernlund <Joakim.Tjernlund(a)infinera.com>
Cc: linux-mtd(a)lists.infradead.org
Cc: stable(a)vger.kernel.org
---
Changes since v6:
- Change the tag of Hauke Mehrtens to Signed-off-by as confirmed with him.
- Removed the tag of Koen Vandeputte as confirmed with him.
- Address the ./scripts/checkpatch.pl issues.
- Fix to remain the file type as 100644.
Changes since v5:
- Rebased on top of Liu Jian's fixes in master.
- Change to follow Liu Jian's fixes in master for the write buffer.
- Change the email address of Tokunori Ikegami to ikegami.t(a)gmail.com.
Changes since v4:
- None.
Changes since v3:
- Update the commit message for the comments.
- Drop the addition of blanks lines around xip_enable().
- Delete unnecessary setting the ret variable to -EIO.
- Change the email address of Tokunori Ikegami to ikegami_to(a)yahoo.co.jp.
Changes since v2:
- Just update the commit message for the comment.
Changes since v1:
- Just update the commit message.
Background:
This is required for OpenWrt Project to result the flash write issue as
below patche.
<https://git.openwrt.org/?p=openwrt/openwrt.git;a=commitdiff;h=ddc11c3932c7b…>
Also the original patch in OpenWRT is below.
<https://github.com/openwrt/openwrt/blob/v18.06.0/target/linux/ar71xx/patche…>
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().
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 c8fa5906bdf9..ed3e640eb03a 100644
--- a/drivers/mtd/chips/cfi_cmdset_0002.c
+++ b/drivers/mtd/chips/cfi_cmdset_0002.c
@@ -1628,29 +1628,35 @@ static int __xipram do_write_oneword(struct map_info *map, struct flchip *chip,
continue;
}
- if (time_after(jiffies, timeo) && !chip_ready(map, adr)){
+ /*
+ * We check "time_after" and "!chip_good" before checking
+ * "chip_good" to avoid the failure due to scheduling.
+ */
+ if (time_after(jiffies, timeo) && !chip_good(map, adr, datum)) {
xip_enable(map, chip, adr);
printk(KERN_WARNING "MTD %s(): software timeout\n", __func__);
xip_disable(map, chip, adr);
+ ret = -EIO;
break;
}
- if (chip_ready(map, adr))
+ if (chip_good(map, adr, datum))
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:
--
2.11.0
This is a note to let you know that I've just added the patch titled
firmware: improve LSM/IMA security behaviour
to my driver-core git tree which can be found at
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core.git
in the driver-core-next branch.
The patch will show up in the next release of the linux-next tree
(usually sometime within the next 24 hours during the week.)
The patch will also be merged in the next major kernel release
during the merge window.
If you have any questions about this process, please let me know.
>From 2472d64af2d3561954e2f05365a67692bb852f2a Mon Sep 17 00:00:00 2001
From: Sven Van Asbroeck <thesven73(a)gmail.com>
Date: Mon, 17 Jun 2019 14:23:54 -0400
Subject: firmware: improve LSM/IMA security behaviour
The firmware loader queries if LSM/IMA permits it to load firmware
via the sysfs fallback. Unfortunately, the code does the opposite:
it expressly permits sysfs fw loading if security_kernel_load_data(
LOADING_FIRMWARE) returns -EACCES. This happens because a
zero-on-success return value is cast to a bool that's true on success.
Fix the return value handling so we get the correct behaviour.
Fixes: 6e852651f28e ("firmware: add call to LSM hook before firmware sysfs fallback")
Cc: Stable <stable(a)vger.kernel.org>
Cc: Mimi Zohar <zohar(a)linux.vnet.ibm.com>
Cc: Kees Cook <keescook(a)chromium.org>
To: Luis Chamberlain <mcgrof(a)kernel.org>
Cc: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org>
Cc: "Rafael J. Wysocki" <rafael(a)kernel.org>
Cc: linux-kernel(a)vger.kernel.org
Signed-off-by: Sven Van Asbroeck <TheSven73(a)gmail.com>
Reviewed-by: Mimi Zohar <zohar(a)linux.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org>
---
drivers/base/firmware_loader/fallback.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/base/firmware_loader/fallback.c b/drivers/base/firmware_loader/fallback.c
index b5cd96fd0e77..29becea1910d 100644
--- a/drivers/base/firmware_loader/fallback.c
+++ b/drivers/base/firmware_loader/fallback.c
@@ -659,7 +659,7 @@ static bool fw_run_sysfs_fallback(enum fw_opt opt_flags)
/* Also permit LSMs and IMA to fail firmware sysfs fallback */
ret = security_kernel_load_data(LOADING_FIRMWARE);
if (ret < 0)
- return ret;
+ return false;
return fw_force_sysfs_fallback(opt_flags);
}
--
2.22.0