| Message ID | 20220511182713.26790-1-pali@kernel.org |
|---|---|
| State | Accepted |
| Commit | a29eb319a3f8ccfb657053b2941581fa1933974e |
| Delegated to: | Peng Fan |
| Headers | show |
| Series | [1/2] mmc: fsl_esdhc: Set fallback mode to 1-bit | expand |
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))
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; + printf("No max bus width provided. Fallback to 1-bit mode.\n"); } if (IS_ENABLED(CONFIG_ESDHC_DETECT_8_BIT_QUIRK))
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> --- drivers/mmc/fsl_esdhc.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-)