| From | Greg Kroah-Hartman <> | Subject | [PATCH 5.4 022/184] mmc: core: Set read only for SD cards with permanent write protect bit | Date | Mon, 10 May 2021 12:18:36 +0200 |
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From: Seunghui Lee <sh043.lee@samsung.com>
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> --- drivers/mmc/core/sd.c | 6 ++++++ 1 file changed, 6 insertions(+)
--- a/drivers/mmc/core/sd.c +++ b/drivers/mmc/core/sd.c @@ -135,6 +135,9 @@ static int mmc_decode_csd(struct mmc_car 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_car 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",
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