mmc: sdio: fix setting card data bus width as 4-bit (2a0fe914) · Commits · 戴 / test

SDIO_CCCR_IF[1:0] in SDIO card is used for card data bus width setting as below: 00b: 1-bit bus 01b: Reserved 10b: 4-bit bus 11b: 8-bit bus (only for embedded SDIO) And sdio_enable_wide is for setting data bus width as 4-bit. But currently, it first reads the register, second OR' 1b with SDIO_CCCR_IF[1], and then writes it back. As we can see, this is based on such assumption that the SDIO_CCCR_IF[0] is always 0. Apparently, this is not right. Signed-off-by:

Yong Ding <yongd@marvell.com> Acked-by:

Philip Rakity <prakity@marvell.com> Signed-off-by:

Chris Ball <cjb@laptop.org>

drivers/mmc/core/sdio.c

+6 −0

Original line number	Diff line number	Diff line
		@@ -218,6 +218,12 @@ static int sdio_enable_wide(struct mmc_card *card)
		if (ret)
		return ret;

		if ((ctrl & SDIO_BUS_WIDTH_MASK) == SDIO_BUS_WIDTH_RESERVED)
		pr_warning("%s: SDIO_CCCR_IF is invalid: 0x%02x\n",
		mmc_hostname(card->host), ctrl);

		/* set as 4-bit bus width */
		ctrl &= ~SDIO_BUS_WIDTH_MASK;
		ctrl \|= SDIO_BUS_WIDTH_4BIT;

		ret = mmc_io_rw_direct(card, 1, 0, SDIO_CCCR_IF, ctrl, NULL);

include/linux/mmc/sdio.h

+2 −0

Original line number	Diff line number	Diff line
		@@ -98,7 +98,9 @@

		#define SDIO_CCCR_IF 0x07 /* bus interface controls */

		#define SDIO_BUS_WIDTH_MASK 0x03 /* data bus width setting */
		#define SDIO_BUS_WIDTH_1BIT 0x00
		#define SDIO_BUS_WIDTH_RESERVED 0x01
		#define SDIO_BUS_WIDTH_4BIT 0x02
		#define SDIO_BUS_ECSI 0x20 /* Enable continuous SPI interrupt */
		#define SDIO_BUS_SCSI 0x40 /* Support continuous SPI interrupt */

Admin message