On 5/12/22 03:27, Pali Rohár wrote:
8-bit mode is not supported by SD cards and on P2020 are four SDHC pins shared with SPI (so if P2020 board have also SPI then only 4-bit SDHC mode is provided). So 8-bit SDHC mode is really bad default.
When max bus width is not provided then set mode to 1-bit. This mode is supported by all cards, so it is the best option for fallback mode.
Also P2020 bootrom sets mode to 1-bit when booting from SD/MMC card.
Signed-off-by: Pali Rohár pali@kernel.org
Reviewed-by: Jaehoon Chung jh80.chung@samsung.com
Add minor comment.
drivers/mmc/fsl_esdhc.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-)
diff --git a/drivers/mmc/fsl_esdhc.c b/drivers/mmc/fsl_esdhc.c index 3b3587bd8d72..834f8933b0c6 100644 --- a/drivers/mmc/fsl_esdhc.c +++ b/drivers/mmc/fsl_esdhc.c @@ -963,9 +963,8 @@ int fsl_esdhc_initialize(struct bd_info *bis, struct fsl_esdhc_cfg *cfg) } else if (cfg->max_bus_width == 1) { mmc_cfg->host_caps |= MMC_MODE_1BIT; } else {
mmc_cfg->host_caps |= MMC_MODE_1BIT | MMC_MODE_4BIT |MMC_MODE_8BIT;printf("No max bus width provided. Assume 8-bit supported.\n");
mmc_cfg->host_caps |= MMC_MODE_1BIT;
I'm not sure that it really needs to use "|".
Best Regards, Jaehoon Chung
printf("No max bus width provided. Fallback to 1-bit mode.\n");}
if (IS_ENABLED(CONFIG_ESDHC_DETECT_8_BIT_QUIRK))