linux-kernel - Re: [PATCH v3 4/7] mmc: sdhci: Add quirk for disabling DTO during erase command

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Date:   Fri, 13 Dec 2019 11:40:03 +0200
From:   Adrian Hunter <adrian.hunter@...el.com>
To:     Faiz Abbas <faiz_abbas@...com>, linux-kernel@...r.kernel.org,
        devicetree@...r.kernel.org, linux-mmc@...r.kernel.org
Cc:     kishon@...com, mark.rutland@....com, robh+dt@...nel.org,
        ulf.hansson@...aro.org, zhang.chunyan@...aro.org, tony@...mide.com
Subject: Re: [PATCH v3 4/7] mmc: sdhci: Add quirk for disabling DTO during
 erase command

On 10/12/19 11:51 am, Faiz Abbas wrote:
> Some controllers might prematurely issue a data timeout during an erase
> command. Add a quirk to disable the interrupt when an erase command is
> issued.
> 
> Signed-off-by: Faiz Abbas <faiz_abbas@...com>
> ---
>  drivers/mmc/host/sdhci.c | 5 +++++
>  drivers/mmc/host/sdhci.h | 2 ++
>  2 files changed, 7 insertions(+)
> 
> diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
> index 6f3d4991bee1..b8934c50b9c4 100644
> --- a/drivers/mmc/host/sdhci.c
> +++ b/drivers/mmc/host/sdhci.c
> @@ -1532,6 +1532,11 @@ void sdhci_send_command(struct sdhci_host *host, struct mmc_command *cmd)
>  	/* Initially, a command has no error */
>  	cmd->error = 0;
>  
> +	if (cmd->opcode == MMC_ERASE &&
> +	    (host->quirks2 & SDHCI_QUIRK2_DISABLE_DTO_FOR_ERASE)) {
> +		sdhci_set_data_timeout_irq(host, false);
> +	}

If you factor out __sdhci_set_timeout() like below then
you could implement ->set_timeout() to do this.

diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index ad6d2f93aa0b..389e3239eadc 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -1002,27 +1002,28 @@ static void sdhci_set_data_timeout_irq(struct sdhci_host *host, bool enable)
 	sdhci_writel(host, host->ier, SDHCI_SIGNAL_ENABLE);
 }
 
-static void sdhci_set_timeout(struct sdhci_host *host, struct mmc_command *cmd)
+void __sdhci_set_timeout(struct sdhci_host *host, struct mmc_command *cmd)
 {
-	u8 count;
-
-	if (host->ops->set_timeout) {
-		host->ops->set_timeout(host, cmd);
-	} else {
-		bool too_big = false;
-
-		count = sdhci_calc_timeout(host, cmd, &too_big);
+	bool too_big = false;
+	u8 count = sdhci_calc_timeout(host, cmd, &too_big);
+
+	if (too_big && host->quirks2 & SDHCI_QUIRK2_DISABLE_HW_TIMEOUT) {
+		sdhci_calc_sw_timeout(host, cmd);
+		sdhci_set_data_timeout_irq(host, false);
+	} else if (!(host->ier & SDHCI_INT_DATA_TIMEOUT)) {
+		sdhci_set_data_timeout_irq(host, true);
+	}
 
-		if (too_big &&
-		    host->quirks2 & SDHCI_QUIRK2_DISABLE_HW_TIMEOUT) {
-			sdhci_calc_sw_timeout(host, cmd);
-			sdhci_set_data_timeout_irq(host, false);
-		} else if (!(host->ier & SDHCI_INT_DATA_TIMEOUT)) {
-			sdhci_set_data_timeout_irq(host, true);
-		}
+	sdhci_writeb(host, count, SDHCI_TIMEOUT_CONTROL);
+}
+EXPORT_SYMBOL_GPL(__sdhci_set_timeout);
 
-		sdhci_writeb(host, count, SDHCI_TIMEOUT_CONTROL);
-	}
+static void sdhci_set_timeout(struct sdhci_host *host, struct mmc_command *cmd)
+{
+	if (host->ops->set_timeout)
+		host->ops->set_timeout(host, cmd);
+	else
+		__sdhci_set_timeout(host, cmd);
 }
 
 static void sdhci_prepare_data(struct sdhci_host *host, struct mmc_command *cmd)



> +
>  	if ((host->quirks2 & SDHCI_QUIRK2_STOP_WITH_TC) &&
>  	    cmd->opcode == MMC_STOP_TRANSMISSION)
>  		cmd->flags |= MMC_RSP_BUSY;
> diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h
> index b28706a1bc6f..beda9afba3a6 100644
> --- a/drivers/mmc/host/sdhci.h
> +++ b/drivers/mmc/host/sdhci.h
> @@ -482,6 +482,8 @@ struct sdhci_host {
>   * block count.
>   */
>  #define SDHCI_QUIRK2_USE_32BIT_BLK_CNT			(1<<18)
> +/* Controller needs to disable DTO for erase command */
> +#define SDHCI_QUIRK2_DISABLE_DTO_FOR_ERASE		(1<<19)
>  
>  	int irq;		/* Device IRQ */
>  	void __iomem *ioaddr;	/* Mapped address */
>