Commit 0ed50abb authored Aug 30, 2016 by Daniel Glöckner Committed by Ulf Hansson Sep 26, 2016

mmc: block: don't use CMD23 with very old MMC cards



CMD23 aka SET_BLOCK_COUNT was introduced with MMC v3.1.
Older versions of the specification allowed to terminate
multi-block transfers only with CMD12.

The patch fixes the following problem:

  mmc0: new MMC card at address 0001
  mmcblk0: mmc0:0001 SDMB-16 15.3 MiB
  mmcblk0: timed out sending SET_BLOCK_COUNT command, card status 0x400900
  ...
  blk_update_request: I/O error, dev mmcblk0, sector 0
  Buffer I/O error on dev mmcblk0, logical block 0, async page read
   mmcblk0: unable to read partition table

Signed-off-by: Daniel Glöckner <dg@emlix.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

parent 92add82e

drivers/mmc/card/block.c

+2 −1

Original line number	Diff line number	Diff line
		@@ -2303,7 +2303,8 @@ again:
		set_capacity(md->disk, size);

		if (mmc_host_cmd23(card->host)) {
		if (mmc_card_mmc(card) \|\|
		if ((mmc_card_mmc(card) &&
		card->csd.mmca_vsn >= CSD_SPEC_VER_3) \|\|
		(mmc_card_sd(card) &&
		card->scr.cmds & SD_SCR_CMD23_SUPPORT))
		md->flags \|= MMC_BLK_CMD23;

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