From: Sergei Antonov <saproj@xxxxxxxxx> commit 35ca91d1338ae158f6dcc0de5d1e86197924ffda upstream. According to the datasheet [1] at page 377, 4-bit bus width is turned on by bit 2 of the Bus Width Register. Thus the current bitmask is wrong: define BUS_WIDTH_4 BIT(1) BIT(1) does not work but BIT(2) works. This has been verified on real MOXA hardware with FTSDC010 controller revision 1_6_0. The corrected value of BUS_WIDTH_4 mask collides with: define BUS_WIDTH_8 BIT(2). Additionally, 8-bit bus width mode isn't supported according to the datasheet, so let's remove the corresponding code. [1] https://bitbucket.org/Kasreyn/mkrom-uc7112lx/src/master/documents/FIC8120_DS_v1.2.pdf Fixes: 1b66e94e6b99 ("mmc: moxart: Add MOXA ART SD/MMC driver") Signed-off-by: Sergei Antonov <saproj@xxxxxxxxx> Cc: Jonas Jensen <jonas.jensen@xxxxxxxxx> Cc: stable@xxxxxxxxxxxxxxx Link: https://lore.kernel.org/r/20220907205753.1577434-1-saproj@xxxxxxxxx Signed-off-by: Ulf Hansson <ulf.hansson@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/mmc/host/moxart-mmc.c | 17 +++-------------- 1 file changed, 3 insertions(+), 14 deletions(-) --- a/drivers/mmc/host/moxart-mmc.c +++ b/drivers/mmc/host/moxart-mmc.c @@ -111,8 +111,8 @@ #define CLK_DIV_MASK 0x7f /* REG_BUS_WIDTH */ -#define BUS_WIDTH_8 BIT(2) -#define BUS_WIDTH_4 BIT(1) +#define BUS_WIDTH_4_SUPPORT BIT(3) +#define BUS_WIDTH_4 BIT(2) #define BUS_WIDTH_1 BIT(0) #define MMC_VDD_360 23 @@ -527,9 +527,6 @@ static void moxart_set_ios(struct mmc_ho case MMC_BUS_WIDTH_4: writel(BUS_WIDTH_4, host->base + REG_BUS_WIDTH); break; - case MMC_BUS_WIDTH_8: - writel(BUS_WIDTH_8, host->base + REG_BUS_WIDTH); - break; default: writel(BUS_WIDTH_1, host->base + REG_BUS_WIDTH); break; @@ -646,16 +643,8 @@ static int moxart_probe(struct platform_ dmaengine_slave_config(host->dma_chan_rx, &cfg); } - switch ((readl(host->base + REG_BUS_WIDTH) >> 3) & 3) { - case 1: + if (readl(host->base + REG_BUS_WIDTH) & BUS_WIDTH_4_SUPPORT) mmc->caps |= MMC_CAP_4_BIT_DATA; - break; - case 2: - mmc->caps |= MMC_CAP_4_BIT_DATA | MMC_CAP_8_BIT_DATA; - break; - default: - break; - } writel(0, host->base + REG_INTERRUPT_MASK);