Re: [PATCH] mmc: sdhci-pci: Only do AMD tuning for HS200

[Adrian Hunter <adrian.hunter@intel.com>]

On 07/04/18 01:07, Daniel Kurtz wrote:
> Commit c31165d7400b ("mmc: sdhci-pci: Add support for HS200 tuning mode
> on AMD, eMMC-4.5.1") added a HS200 tuning method for use with AMD SDHCI
> controllers.  As described in the commit subject, this tuning is specific
> for HS200.  However, as implemented, this method is used for all host
> timings, because platform_execute_tuning, if it exists, is called
> unconditionally by sdhci_execute_tuning().  This breaks tuning when using
> the AMD controller with, for example, a DDR50 SD card.
> 
> Instead, we can implement an amd execute_tuning wrapper callback, and
> then conditionally do the HS200 specific tuning for HS200, and otherwise
> call back to the standard sdhci_execute_tuning().
> 
> Signed-off-by: Daniel Kurtz <djkurtz@chromium.org>

Acked-by: Adrian Hunter <adrian.hunter@intel.com>

> ---
>  drivers/mmc/host/sdhci-pci-core.c | 25 +++++++++++++++++++++++--
>  1 file changed, 23 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/mmc/host/sdhci-pci-core.c b/drivers/mmc/host/sdhci-pci-core.c
> index 787434e5589d..78c25ad35fd2 100644
> --- a/drivers/mmc/host/sdhci-pci-core.c
> +++ b/drivers/mmc/host/sdhci-pci-core.c
> @@ -1312,7 +1312,7 @@ static void amd_enable_manual_tuning(struct pci_dev *pdev)
>  	pci_write_config_dword(pdev, AMD_SD_MISC_CONTROL, val);
>  }
>  
> -static int amd_execute_tuning(struct sdhci_host *host, u32 opcode)
> +static int amd_execute_tuning_hs200(struct sdhci_host *host, u32 opcode)
>  {
>  	struct sdhci_pci_slot *slot = sdhci_priv(host);
>  	struct pci_dev *pdev = slot->chip->pdev;
> @@ -1351,6 +1351,27 @@ static int amd_execute_tuning(struct sdhci_host *host, u32 opcode)
>  	return 0;
>  }
>  
> +static int amd_execute_tuning(struct mmc_host *mmc, u32 opcode)
> +{
> +	struct sdhci_host *host = mmc_priv(mmc);
> +
> +	/* AMD requires custom HS200 tuning */
> +	if (host->timing == MMC_TIMING_MMC_HS200)
> +		return amd_execute_tuning_hs200(host, opcode);
> +
> +	/* Otherwise perform standard SDHCI tuning */
> +	return sdhci_execute_tuning(mmc, opcode);
> +}
> +
> +static int amd_probe_slot(struct sdhci_pci_slot *slot)
> +{
> +	struct mmc_host_ops *ops = &slot->host->mmc_host_ops;
> +
> +	ops->execute_tuning = amd_execute_tuning;
> +
> +	return 0;
> +}
> +
>  static int amd_probe(struct sdhci_pci_chip *chip)
>  {
>  	struct pci_dev	*smbus_dev;
> @@ -1385,12 +1406,12 @@ static const struct sdhci_ops amd_sdhci_pci_ops = {
>  	.set_bus_width			= sdhci_set_bus_width,
>  	.reset				= sdhci_reset,
>  	.set_uhs_signaling		= sdhci_set_uhs_signaling,
> -	.platform_execute_tuning	= amd_execute_tuning,
>  };
>  
>  static const struct sdhci_pci_fixes sdhci_amd = {
>  	.probe		= amd_probe,
>  	.ops		= &amd_sdhci_pci_ops,
> +	.probe_slot	= amd_probe_slot,
>  };
>  
>  static const struct pci_device_id pci_ids[] = {
>