[U-Boot] [PATCH v3 06/13] mmc: sdhci: Add support for sdhci-caps-mask

[Andrew F. Davis]

On 2/12/19 2:58 AM, Faiz Abbas wrote:
> Add Support for masking some bits in the capabilities
> register of a host controller.
> 
> Also remove the redundant readl() into caps1.
> 
> Signed-off-by: Faiz Abbas <faiz_abbas at ti.com>
> Reviewed-by: Tom Rini <trini at konsulko.com>
> ---
>  drivers/mmc/sdhci.c | 15 ++++++++++-----
>  1 file changed, 10 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/mmc/sdhci.c b/drivers/mmc/sdhci.c
> index cdeba914f9..c8a8a299ba 100644
> --- a/drivers/mmc/sdhci.c
> +++ b/drivers/mmc/sdhci.c
> @@ -8,6 +8,7 @@
>   */
>  
>  #include <common.h>
> +#include <dm.h>
>  #include <errno.h>
>  #include <malloc.h>
>  #include <mmc.h>
> @@ -561,8 +562,15 @@ int sdhci_setup_cfg(struct mmc_config *cfg, struct sdhci_host *host,
>  		u32 f_max, u32 f_min)
>  {
>  	u32 caps, caps_1 = 0;
> +	u32 mask[2] = {0};
> +	int ret;
> +
> +	ret = dev_read_u32_array(host->mmc->dev, "sdhci-caps-mask",
> +				 mask, 2);


You can't do this, host->mmc is not setup at this point, you will get a
null pointer deref here. (On K3 dereferencing zero does not throw an
error so it masks this problem, other platforms (and HS K3) are not so
lucky)

Andrew

> +	if (ret && ret != -1)
> +		return ret;
>  
> -	caps = sdhci_readl(host, SDHCI_CAPABILITIES);
> +	caps = ~mask[1] & sdhci_readl(host, SDHCI_CAPABILITIES);
>  
>  #ifdef CONFIG_MMC_SDHCI_SDMA
>  	if (!(caps & SDHCI_CAN_DO_SDMA)) {
> @@ -584,7 +592,7 @@ int sdhci_setup_cfg(struct mmc_config *cfg, struct sdhci_host *host,
>  
>  	/* Check whether the clock multiplier is supported or not */
>  	if (SDHCI_GET_VERSION(host) >= SDHCI_SPEC_300) {
> -		caps_1 = sdhci_readl(host, SDHCI_CAPABILITIES_1);
> +		caps_1 = ~mask[0] & sdhci_readl(host, SDHCI_CAPABILITIES_1);
>  		host->clk_mul = (caps_1 & SDHCI_CLOCK_MUL_MASK) >>
>  				SDHCI_CLOCK_MUL_SHIFT;
>  	}
> @@ -641,9 +649,6 @@ int sdhci_setup_cfg(struct mmc_config *cfg, struct sdhci_host *host,
>  		cfg->host_caps &= ~MMC_MODE_HS_52MHz;
>  	}
>  
> -	if (SDHCI_GET_VERSION(host) >= SDHCI_SPEC_300)
> -		caps_1 = sdhci_readl(host, SDHCI_CAPABILITIES_1);
> -
>  	if (!(cfg->voltages & MMC_VDD_165_195) ||
>  	    (host->quirks & SDHCI_QUIRK_NO_1_8_V))
>  		caps_1 &= ~(SDHCI_SUPPORT_SDR104 | SDHCI_SUPPORT_SDR50 |
>