From: Seunghui Lee Date: Mon, 22 Feb 2021 08:31:56 +0000 (+0900) Subject: mmc: core: Set read only for SD cards with permanent write protect bit X-Git-Url: http://git.osdn.net/view?a=commitdiff_plain;h=917a5336f2c27928be270226ab374ed0cbf3805d;p=uclinux-h8%2Flinux.git mmc: core: Set read only for SD cards with permanent write protect bit Some of SD cards sets permanent write protection bit in their CSD register, due to lifespan or internal problem. To avoid unnecessary I/O write operations, let's parse the bits in the CSD during initialization and mark the card as read only for this case. Signed-off-by: Seunghui Lee Link: https://lore.kernel.org/r/20210222083156.19158-1-sh043.lee@samsung.com Cc: stable@vger.kernel.org Signed-off-by: Ulf Hansson --- diff --git a/drivers/mmc/core/sd.c b/drivers/mmc/core/sd.c index 6fa51a6ed058..2c48d6504101 100644 --- a/drivers/mmc/core/sd.c +++ b/drivers/mmc/core/sd.c @@ -135,6 +135,9 @@ static int mmc_decode_csd(struct mmc_card *card) csd->erase_size = UNSTUFF_BITS(resp, 39, 7) + 1; csd->erase_size <<= csd->write_blkbits - 9; } + + if (UNSTUFF_BITS(resp, 13, 1)) + mmc_card_set_readonly(card); break; case 1: /* @@ -169,6 +172,9 @@ static int mmc_decode_csd(struct mmc_card *card) csd->write_blkbits = 9; csd->write_partial = 0; csd->erase_size = 1; + + if (UNSTUFF_BITS(resp, 13, 1)) + mmc_card_set_readonly(card); break; default: pr_err("%s: unrecognised CSD structure version %d\n",