From f547db87cb46716100817d8acf302f7fb02fd836 Mon Sep 17 00:00:00 2001 From: Tokunori Ikegami Date: Tue, 8 Oct 2019 20:18:52 +0800 Subject: [PATCH] mtd: cfi_cmdset_0002: Use chip_good() to retry in do_write_oneword() commit 37c673ade35c707d50583b5b25091ff8ebdeafd7 upstream. 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. Cc: Chris Packham Cc: Joakim Tjernlund Cc: linux-mtd@lists.infradead.org Cc: stable@vger.kernel.org Reported-by: Fabio Bettoni Signed-off-by: Felix Fietkau Signed-off-by: Hauke Mehrtens Signed-off-by: Tokunori Ikegami [vigneshr@ti.com: Fix a checkpatch warning] Signed-off-by: Vignesh Raghavendra Signed-off-by: Greg Kroah-Hartman Signed-off-by: Yang Yingliang --- 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..ba44ea6d497e 100644 --- a/drivers/mtd/chips/cfi_cmdset_0002.c +++ b/drivers/mtd/chips/cfi_cmdset_0002.c @@ -1627,29 +1627,35 @@ 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: -- GitLab