Re: [PATCH v2 4/4] mmc: sdhci-tegra: Use actual clock rate for SW tuning correction

Thierry Reding
2022-09-14T12:24:14Z

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On Wed, Sep 14, 2022 at 03:26:28PM +0530, Prathamesh Shete 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.

Ideally there shouldn't be a deviation between host_clk and the actual
clock rate that was set. Perhaps it'd be good to provide a bit more
information on what the deviation can be and when that happens, as well
as what the consequences are. That would make it a bit more obvious why
this fix is needed.

Thierry

>
> 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>
> ---
> 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 7d16dc41fe91..42b018d4ebc3 100644
> --- a/drivers/mmc/host/sdhci-tegra.c
> +++ b/drivers/mmc/host/sdhci-tegra.c
> @@ -778,7 +778,7 @@ 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
>

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