Re: [PATCH v2 1/3] mmc: sdhci-of-dwcmshc: improve delay and sleep handling with fsleep()

[Adrian Hunter]

On 21/05/2026 11:35, Artem Shimko wrote:
> Replace usleep_range() and udelay(1) (for consistency) with fsleep()
> in several places to follow kernel documentation recommendation [1]
> of using fsleep() for delays in non-atomic contexts.

The usleep_range()'s have presumably been chosen and validated.
They cannot be arbitrarily changed.  And then there is no point
changing udelay() to fsleep().  Please let's just leave this.

> 
> The fsleep() function automatically selects the optimal delay mechanism:
> udelay() for delays <= 10 us, usleep_range() for 10-20000 us, and msleep()
> for longer delays. This makes the code more consistent and simplifies
> future adjustments if delay durations ever change.
> 
> [1] https://docs.kernel.org/timers/delay_sleep_functions.html
> 
> Signed-off-by: Artem Shimko <a.shimko.dev@xxxxxxxxx>
> ---
>  drivers/mmc/host/sdhci-of-dwcmshc.c | 14 +++++++-------
>  1 file changed, 7 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/mmc/host/sdhci-of-dwcmshc.c b/drivers/mmc/host/sdhci-of-dwcmshc.c
> index 0b2158a7e409..4cccd6e42e60 100644
> --- a/drivers/mmc/host/sdhci-of-dwcmshc.c
> +++ b/drivers/mmc/host/sdhci-of-dwcmshc.c
> @@ -816,7 +816,7 @@ static void dwcmshc_rk3568_set_clock(struct sdhci_host *host, unsigned int clock
>  
>  	/* Reset DLL */
>  	sdhci_writel(host, BIT(1), DWCMSHC_EMMC_DLL_CTRL);
> -	udelay(1);
> +	fsleep(1);
>  	sdhci_writel(host, 0x0, DWCMSHC_EMMC_DLL_CTRL);
>  
>  	/*
> @@ -895,7 +895,7 @@ static void rk35xx_sdhci_reset(struct sdhci_host *host, u8 mask)
>  
>  	if (mask & SDHCI_RESET_ALL && priv->reset) {
>  		reset_control_assert(priv->reset);
> -		udelay(1);
> +		fsleep(1);
>  		reset_control_deassert(priv->reset);
>  	}
>  
> @@ -1136,7 +1136,7 @@ static void cv18xx_sdhci_set_tap(struct sdhci_host *host, int tap)
>  
>  	clk |= SDHCI_CLOCK_CARD_EN;
>  	sdhci_writew(host, clk, SDHCI_CLOCK_CONTROL);
> -	usleep_range(1000, 2000);
> +	fsleep(1500);
>  }
>  
>  static int cv18xx_retry_tuning(struct mmc_host *mmc, u32 opcode, int *cmd_error)
> @@ -1490,7 +1490,7 @@ static void sdhci_eic7700_config_phy(struct sdhci_host *host)
>  		val |= PHY_PAD_RXSEL_1V8;
>  		sdhci_writew(host, val, PHY_STBPAD_CNFG_R);
>  	}
> -	usleep_range(2000, 3000);
> +	fsleep(2500);
>  	sdhci_writel(host, drv | PHY_CNFG_RSTN_DEASSERT, PHY_CNFG_R);
>  	sdhci_eic7700_config_phy_delay(host, dwc_priv->delay_line);
>  }
> @@ -1520,7 +1520,7 @@ static int sdhci_eic7700_reset_init(struct device *dev, struct eic7700_priv *pri
>  		dev_err(dev, "Failed to assert reset signals: %d\n", ret);
>  		return ret;
>  	}
> -	usleep_range(2000, 2100);
> +	fsleep(2050);
>  	ret = reset_control_deassert(priv->reset);
>  	if (ret) {
>  		dev_err(dev, "Failed to deassert reset signals: %d\n", ret);
> @@ -1565,7 +1565,7 @@ static int sdhci_eic7700_delay_tuning(struct sdhci_host *host, u32 opcode)
>  		ret = mmc_send_tuning(host->mmc, opcode, &cmd_error);
>  		if (ret) {
>  			host->ops->reset(host, SDHCI_RESET_CMD | SDHCI_RESET_DATA);
> -			usleep_range(200, 210);
> +			fsleep(205);
>  			if (delay_min != -1 && delay_max != -1)
>  				break;
>  		} else {
> @@ -1736,7 +1736,7 @@ static void sdhci_eic7700_set_uhs_signaling(struct sdhci_host *host, unsigned in
>  		 */
>  		sdhci_writew(host, 0xffff, PHY_DLLBT_CNFG_R);
>  		sdhci_writeb(host, PHY_DLL_CTRL_ENABLE, PHY_DLL_CTRL_R);
> -		usleep_range(100, 110);
> +		fsleep(105);
>  
>  		ret = read_poll_timeout(sdhci_readb, status, status & DLL_LOCK_STS, 100, 1000000,
>  					false, host, PHY_DLL_STATUS_R);