Re: [PATCH v2] mmc: sdhci-msm: fix mutex while in spinlock

From: Adrian Hunter
Date: Tue Jul 02 2019 - 03:09:30 EST


On 1/07/19 6:01 PM, Jorge Ramirez-Ortiz wrote:
> mutexes can sleep and therefore should not be taken while holding a
> spinlock. move clk_get_rate (can sleep) outside the spinlock protected
> region.
>
> Fixes: 83736352e0ca ("mmc: sdhci-msm: Update DLL reset sequence")
> Cc: stable@xxxxxxxxxxxxxxx
> Signed-off-by: Jorge Ramirez-Ortiz <jorge.ramirez-ortiz@xxxxxxxxxx>
> Reviewed-by: Bjorn Andersson <bjorn.andersson@xxxxxxxxxx>

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

> ---
> drivers/mmc/host/sdhci-msm.c | 9 ++++++---
> 1 file changed, 6 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/mmc/host/sdhci-msm.c b/drivers/mmc/host/sdhci-msm.c
> index 5fc76a1993d0..9cf14b359c14 100644
> --- a/drivers/mmc/host/sdhci-msm.c
> +++ b/drivers/mmc/host/sdhci-msm.c
> @@ -575,11 +575,14 @@ static int msm_init_cm_dll(struct sdhci_host *host)
> struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
> struct sdhci_msm_host *msm_host = sdhci_pltfm_priv(pltfm_host);
> int wait_cnt = 50;
> - unsigned long flags;
> + unsigned long flags, xo_clk = 0;
> u32 config;
> const struct sdhci_msm_offset *msm_offset =
> msm_host->offset;
>
> + if (msm_host->use_14lpp_dll_reset && !IS_ERR_OR_NULL(msm_host->xo_clk))
> + xo_clk = clk_get_rate(msm_host->xo_clk);
> +
> spin_lock_irqsave(&host->lock, flags);
>
> /*
> @@ -627,10 +630,10 @@ static int msm_init_cm_dll(struct sdhci_host *host)
> config &= CORE_FLL_CYCLE_CNT;
> if (config)
> mclk_freq = DIV_ROUND_CLOSEST_ULL((host->clock * 8),
> - clk_get_rate(msm_host->xo_clk));
> + xo_clk);
> else
> mclk_freq = DIV_ROUND_CLOSEST_ULL((host->clock * 4),
> - clk_get_rate(msm_host->xo_clk));
> + xo_clk);
>
> config = readl_relaxed(host->ioaddr +
> msm_offset->core_dll_config_2);
>