Re: [PATCH v7 4/4] mmc: sdhci-tegra: Use actual clock rate for SW tuning correction

Ulf Hansson
2022-10-07T09:05:31Z

On Thu, 6 Oct 2022 at 15:07, Prathamesh Shete <pshete@nvidia.com> wrote:
>
> Ensure tegra_host member "curr_clk_rate" holds the actual clock rate
> instead of requested clock rate for proper use during tuning correction
> algorithm. Actual clk rate may not be the same as the requested clk
> frequency depending on the parent clock source set. Tuning correction
> algorithm depends on certain parameters which are sensitive to current
> clk rate. If the host clk is selected instead of the actual clock rate,
> tuning correction algorithm may end up applying invalid correction,
> which could result in errors
>
> Fixes: ea8fc5953e8b ("mmc: tegra: update hw tuning process")
>
> Signed-off-by: Aniruddha TVS Rao <anrao@nvidia.com>
> Signed-off-by: Prathamesh Shete <pshete@nvidia.com>
> Acked-by: Adrian Hunter <adrian.hunter@intel.com>
> Acked-by: Thierry Reding <treding@nvidia.com>

Applied for fixes and by adding a stable tag, thanks!

Kind regards
Uffe

> ---
> drivers/mmc/host/sdhci-tegra.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/mmc/host/sdhci-tegra.c b/drivers/mmc/host/sdhci-tegra.c
> index 3663c5d0efe0..ccbb26a66284 100644
> --- a/drivers/mmc/host/sdhci-tegra.c
> +++ b/drivers/mmc/host/sdhci-tegra.c
> @@ -783,7 +783,7 @@ static void tegra_sdhci_set_clock(struct sdhci_host *host, unsigned int clock)
> dev_err(dev, "failed to set clk rate to %luHz: %d\n",
> host_clk, err);
>
> - tegra_host->curr_clk_rate = host_clk;
> + tegra_host->curr_clk_rate = clk_get_rate(pltfm_host->clk);
> if (tegra_host->ddr_signaling)
> host->max_clk = host_clk;
> else
> --
> 2.17.1
>