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 <sh043.lee@samsung.com>
Link: https://lore.kernel.org/r/20210222083156.19158-1-sh043.lee@samsung.com
Cc: stable@vger.kernel.org
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

diff --git a/drivers/mmc/core/sd.c b/drivers/mmc/core/sd.c
index 6fa51a6..2c48d65 100644 (file)
--- 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",