From: Brian Norris Date: Fri, 29 Jan 2016 19:25:31 +0000 (-0800) Subject: mtd: spi-nor: silently drop lock/unlock for already locked/unlocked region X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=4c0dba447ef4a97dfbae6e876312e952667eddc4;p=linux-beck.git mtd: spi-nor: silently drop lock/unlock for already locked/unlocked region If, for instance, the entire flash is already unlocked and I try to mtd_unlock() the entire device, I don't expect to see an EINVAL error. It should just silently succeed. Ditto for mtd_lock(). Signed-off-by: Brian Norris Reviewed-by: Ezequiel Garcia Tested-by: Ezequiel Garcia --- diff --git a/drivers/mtd/spi-nor/spi-nor.c b/drivers/mtd/spi-nor/spi-nor.c index a9b3bdf28c90..3dde727f8591 100644 --- a/drivers/mtd/spi-nor/spi-nor.c +++ b/drivers/mtd/spi-nor/spi-nor.c @@ -515,8 +515,12 @@ static int stm_lock(struct spi_nor *nor, loff_t ofs, uint64_t len) status_new = (status_old & ~mask) | val; + /* Don't bother if they're the same */ + if (status_new == status_old) + return 0; + /* Only modify protection if it will not unlock other areas */ - if ((status_new & mask) <= (status_old & mask)) + if ((status_new & mask) < (status_old & mask)) return -EINVAL; write_enable(nor); @@ -569,8 +573,12 @@ static int stm_unlock(struct spi_nor *nor, loff_t ofs, uint64_t len) status_new = (status_old & ~mask) | val; + /* Don't bother if they're the same */ + if (status_new == status_old) + return 0; + /* Only modify protection if it will not lock other areas */ - if ((status_new & mask) >= (status_old & mask)) + if ((status_new & mask) > (status_old & mask)) return -EINVAL; write_enable(nor);