mmc: core: Set read only for SD cards with permanent write protect bit

commit 917a5336f2c27928be270226ab374ed0cbf3805d upstream.

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/mmc/core/sd.c b/drivers/mmc/core/sd.c
index 7f654c714fffcdab78866a83532fac7bb3d03b9a..bb17027c283e9f59938f134dec3b375416d3ac11 100644 (file)
--- a/drivers/mmc/core/sd.c
+++ b/drivers/mmc/core/sd.c
@@ -136,6 +136,9 @@ 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:
                /*
@@ -170,6 +173,9 @@ 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",