On 15/11/19 1:12 PM, haibo.chen@xxxxxxx wrote:
> From: Haibo Chen <haibo.chen@xxxxxxx>
>
> When pm_runtime_suspend is run, a call to SCFW power off the SS (SS is a
> power domain, usdhc belong to this SS power domain) in which the resource
> resides is made. The SCFW can power off the SS if no other resource in
> active in that SS. If so, all state associated with all the resources within
> the SS that is powered off is lost, this includes the clock rates, clock state
> etc. When pm_runtime_resume is called, the SS associated with that resource
> is powered up. But the clocks are left in the default state.
>
> This patch restore clock rate in pm_runtime_resume, make sure the
> clock is right rather than depending on the default state setting
> by SCFW.
>
> Signed-off-by: Haibo Chen <haibo.chen@xxxxxxx>
Acked-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>
> ---
> drivers/mmc/host/sdhci-esdhc-imx.c | 8 +++++++-
> 1 file changed, 7 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/mmc/host/sdhci-esdhc-imx.c b/drivers/mmc/host/sdhci-esdhc-imx.c
> index 2c8a78218c8e..448b29b2da62 100644
> --- a/drivers/mmc/host/sdhci-esdhc-imx.c
> +++ b/drivers/mmc/host/sdhci-esdhc-imx.c
> @@ -162,6 +162,8 @@
> #define ESDHC_FLAG_PMQOS BIT(13)
> /* The IP state got lost in low power mode */
> #define ESDHC_FLAG_STATE_LOST_IN_LPMODE BIT(14)
> +/* The IP lost clock rate in PM_RUNTIME */
> +#define ESDHC_FLAG_CLK_RATE_LOST_IN_PM_RUNTIME BIT(15)
>
> struct esdhc_soc_data {
> u32 flags;
> @@ -225,7 +227,8 @@ static struct esdhc_soc_data usdhc_imx8qxp_data = {
> | ESDHC_FLAG_HAVE_CAP1 | ESDHC_FLAG_HS200
> | ESDHC_FLAG_HS400 | ESDHC_FLAG_HS400_ES
> | ESDHC_FLAG_CQHCI
> - | ESDHC_FLAG_STATE_LOST_IN_LPMODE,
> + | ESDHC_FLAG_STATE_LOST_IN_LPMODE
> + | ESDHC_FLAG_CLK_RATE_LOST_IN_PM_RUNTIME,
> };
>
> struct pltfm_imx_data {
> @@ -1711,6 +1714,9 @@ static int sdhci_esdhc_runtime_resume(struct device *dev)
> pm_qos_add_request(&imx_data->pm_qos_req,
> PM_QOS_CPU_DMA_LATENCY, 0);
>
> + if (imx_data->socdata->flags & ESDHC_FLAG_CLK_RATE_LOST_IN_PM_RUNTIME)
> + clk_set_rate(imx_data->clk_per, pltfm_host->clock);
> +
> err = clk_prepare_enable(imx_data->clk_ahb);
> if (err)
> goto remove_pm_qos_request;
>
