From: Joël Esponde <joel.esponde@xxxxxxxxxxxxx> commit 807c16253319ee6ccf8873ae64f070f7eb532cd5 upstream. With the S25FL127S nor flash part, each writing to the configuration register takes hundreds of ms. During that time, no more accesses to the flash should be done (even reads). This commit adds a wait loop after the register writing until the flash finishes its work. This issue could make rootfs mounting fail when the latter was done too much closely to this quad enable bit setting step. And in this case, a driver as UBIFS may try to recover the filesystem and may broke it completely. Signed-off-by: Joël Esponde <joel.esponde@xxxxxxxxxxxxx> Signed-off-by: Cyrille Pitchen <cyrille.pitchen@xxxxxxxxx> Signed-off-by: Amit Pundir <amit.pundir@xxxxxxxxxx> --- drivers/mtd/spi-nor/spi-nor.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/drivers/mtd/spi-nor/spi-nor.c b/drivers/mtd/spi-nor/spi-nor.c index d0fc165d7d66..21dde5249085 100644 --- a/drivers/mtd/spi-nor/spi-nor.c +++ b/drivers/mtd/spi-nor/spi-nor.c @@ -1255,6 +1255,13 @@ static int spansion_quad_enable(struct spi_nor *nor) return -EINVAL; } + ret = spi_nor_wait_till_ready(nor); + if (ret) { + dev_err(nor->dev, + "timeout while writing configuration register\n"); + return ret; + } + /* read back and check it */ ret = read_cr(nor); if (!(ret > 0 && (ret & CR_QUAD_EN_SPAN))) { -- 2.7.4