Re: [PATCH v1] Revert "mmc: sdhci-tegra: drop ->get_ro() implementation"

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

On 9/08/19 1:24 AM, Dmitry Osipenko wrote:
> The WRITE_PROTECT bit is always in a "protected mode" on Tegra and
> WP-GPIO state need to be used instead. In a case of the GPIO absence,
> write-enable should be assumed. External SD is writable once again as
> a result of this patch because the offending commit changed behaviour for
> the case of a missing WP-GPIO to fall back to WRITE_PROTECT bit-checking,
> which is incorrect for Tegra.
> 
> Cc: stable@vger.kernel.org # v5.1+
> Fixes: e8391453e27f ("mmc: sdhci-tegra: drop ->get_ro() implementation")
> Signed-off-by: Dmitry Osipenko <digetx@gmail.com>

Can we get an Ack from someone from Nvidia

> ---
>  drivers/mmc/host/sdhci-tegra.c | 14 ++++++++++++++
>  1 file changed, 14 insertions(+)
> 
> diff --git a/drivers/mmc/host/sdhci-tegra.c b/drivers/mmc/host/sdhci-tegra.c
> index f4d4761cf20a..02d8f524bb9e 100644
> --- a/drivers/mmc/host/sdhci-tegra.c
> +++ b/drivers/mmc/host/sdhci-tegra.c
> @@ -258,6 +258,16 @@ static void tegra210_sdhci_writew(struct sdhci_host *host, u16 val, int reg)
>  	}
>  }
>  
> +static unsigned int tegra_sdhci_get_ro(struct sdhci_host *host)
> +{
> +	/*
> +	 * Write-enable shall be assumed if GPIO is missing in a board's
> +	 * device-tree because SDHCI's WRITE_PROTECT bit doesn't work on
> +	 * Tegra.
> +	 */
> +	return mmc_gpio_get_ro(host->mmc);
> +}
> +
>  static bool tegra_sdhci_is_pad_and_regulator_valid(struct sdhci_host *host)
>  {
>  	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
> @@ -1224,6 +1234,7 @@ static const struct cqhci_host_ops sdhci_tegra_cqhci_ops = {
>  };
>  
>  static const struct sdhci_ops tegra_sdhci_ops = {
> +	.get_ro     = tegra_sdhci_get_ro,
>  	.read_w     = tegra_sdhci_readw,
>  	.write_l    = tegra_sdhci_writel,
>  	.set_clock  = tegra_sdhci_set_clock,
> @@ -1279,6 +1290,7 @@ static const struct sdhci_tegra_soc_data soc_data_tegra30 = {
>  };
>  
>  static const struct sdhci_ops tegra114_sdhci_ops = {
> +	.get_ro     = tegra_sdhci_get_ro,
>  	.read_w     = tegra_sdhci_readw,
>  	.write_w    = tegra_sdhci_writew,
>  	.write_l    = tegra_sdhci_writel,
> @@ -1332,6 +1344,7 @@ static const struct sdhci_tegra_soc_data soc_data_tegra124 = {
>  };
>  
>  static const struct sdhci_ops tegra210_sdhci_ops = {
> +	.get_ro     = tegra_sdhci_get_ro,
>  	.read_w     = tegra_sdhci_readw,
>  	.write_w    = tegra210_sdhci_writew,
>  	.write_l    = tegra_sdhci_writel,
> @@ -1366,6 +1379,7 @@ static const struct sdhci_tegra_soc_data soc_data_tegra210 = {
>  };
>  
>  static const struct sdhci_ops tegra186_sdhci_ops = {
> +	.get_ro     = tegra_sdhci_get_ro,
>  	.read_w     = tegra_sdhci_readw,
>  	.write_l    = tegra_sdhci_writel,
>  	.set_clock  = tegra_sdhci_set_clock,
>