[v4,08/12] mmc: sdhci: Program a relatively accurate SW timeout value

Message ID 20180425120937.29867-9-kishon@ti.com
State New
Headers show
Series
  • Untitled series #10941
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Commit Message

Kishon Vijay Abraham I April 25, 2018, 12:09 p.m.
sdhci has a 10 second timeout to catch devices that stop responding.
In the case of quirk SDHCI_QUIRK2_DISABLE_HW_TIMEOUT, instead of
programming 10 second arbitrary value, calculate the total time it would
take for the entire transfer to happen and program the timeout value
accordingly.

Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>

---
 drivers/mmc/host/sdhci.c | 36 ++++++++++++++++++++++++++++++++++++
 drivers/mmc/host/sdhci.h | 10 ++++++++++
 2 files changed, 46 insertions(+)

-- 
2.17.0

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Comments

Adrian Hunter April 26, 2018, 7:52 a.m. | #1
On 25/04/18 15:09, Kishon Vijay Abraham I wrote:
> sdhci has a 10 second timeout to catch devices that stop responding.

> In the case of quirk SDHCI_QUIRK2_DISABLE_HW_TIMEOUT, instead of

> programming 10 second arbitrary value, calculate the total time it would

> take for the entire transfer to happen and program the timeout value

> accordingly.

> 

> Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>

> Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>


Looks like I lost a couple of chunks of the patch, sorry :-(
i.e.

diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index 1ed0b8b6570a..a019fd01ccf2 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -1234,13 +1234,6 @@ void sdhci_send_command(struct sdhci_host *host, struct mmc_command *cmd)
 		mdelay(1);
 	}
 
-	timeout = jiffies;
-	if (!cmd->data && cmd->busy_timeout > 9000)
-		timeout += DIV_ROUND_UP(cmd->busy_timeout, 1000) * HZ + HZ;
-	else
-		timeout += 10 * HZ;
-	sdhci_mod_timer(host, cmd->mrq, timeout);
-
 	host->cmd = cmd;
 	if (sdhci_data_line_cmd(cmd)) {
 		WARN_ON(host->data_cmd);
@@ -1280,6 +1273,15 @@ void sdhci_send_command(struct sdhci_host *host, struct mmc_command *cmd)
 	    cmd->opcode == MMC_SEND_TUNING_BLOCK_HS200)
 		flags |= SDHCI_CMD_DATA;
 
+	timeout = jiffies;
+	if (host->data_timeout)
+		timeout += nsecs_to_jiffies(host->data_timeout);
+	else if (!cmd->data && cmd->busy_timeout > 9000)
+		timeout += DIV_ROUND_UP(cmd->busy_timeout, 1000) * HZ + HZ;
+	else
+		timeout += 10 * HZ;
+	sdhci_mod_timer(host, cmd->mrq, timeout);
+
 	sdhci_writew(host, SDHCI_MAKE_CMD(cmd->opcode, flags), SDHCI_COMMAND);
 }
 EXPORT_SYMBOL_GPL(sdhci_send_command);


> ---

>  drivers/mmc/host/sdhci.c | 36 ++++++++++++++++++++++++++++++++++++

>  drivers/mmc/host/sdhci.h | 10 ++++++++++

>  2 files changed, 46 insertions(+)

> 

> diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c

> index c432ec3644aa..1ed0b8b6570a 100644

> --- a/drivers/mmc/host/sdhci.c

> +++ b/drivers/mmc/host/sdhci.c

> @@ -738,6 +738,39 @@ static unsigned int sdhci_target_timeout(struct sdhci_host *host,

>  	return target_timeout;

>  }

>  

> +static void sdhci_calc_sw_timeout(struct sdhci_host *host,

> +				  struct mmc_command *cmd)

> +{

> +	struct mmc_data *data = cmd->data;

> +	struct mmc_host *mmc = host->mmc;

> +	struct mmc_ios *ios = &mmc->ios;

> +	unsigned char bus_width = 1 << ios->bus_width;

> +	unsigned int blksz;

> +	unsigned int freq;

> +	u64 target_timeout;

> +	u64 transfer_time;

> +

> +	target_timeout = sdhci_target_timeout(host, cmd, data);

> +	target_timeout *= NSEC_PER_USEC;

> +

> +	if (data) {

> +		blksz = data->blksz;

> +		freq = host->mmc->actual_clock ? : host->clock;

> +		transfer_time = (u64)blksz * NSEC_PER_SEC * (8 / bus_width);

> +		do_div(transfer_time, freq);

> +		/* multiply by '2' to account for any unknowns */

> +		transfer_time = transfer_time * 2;

> +		/* calculate timeout for the entire data */

> +		host->data_timeout = data->blocks * target_timeout +

> +				     transfer_time;

> +	} else {

> +		host->data_timeout = target_timeout;

> +	}

> +

> +	if (host->data_timeout)

> +		host->data_timeout += MMC_CMD_TRANSFER_TIME;

> +}

> +

>  static u8 sdhci_calc_timeout(struct sdhci_host *host, struct mmc_command *cmd,

>  			     bool *too_big)

>  {

> @@ -831,6 +864,7 @@ static void sdhci_set_timeout(struct sdhci_host *host, struct mmc_command *cmd)

>  

>  		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);

> @@ -845,6 +879,8 @@ static void sdhci_prepare_data(struct sdhci_host *host, struct mmc_command *cmd)

>  	u8 ctrl;

>  	struct mmc_data *data = cmd->data;

>  

> +	host->data_timeout = 0;

> +

>  	if (sdhci_data_line_cmd(cmd))

>  		sdhci_set_timeout(host, cmd);

>  

> diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h

> index f6555c0f4ad3..23966f887da6 100644

> --- a/drivers/mmc/host/sdhci.h

> +++ b/drivers/mmc/host/sdhci.h

> @@ -332,6 +332,14 @@ struct sdhci_adma2_64_desc {

>  /* Allow for a a command request and a data request at the same time */

>  #define SDHCI_MAX_MRQS		2

>  

> +/*

> + * 48bit command and 136 bit response in 100KHz clock could take upto 2.48ms.

> + * However since the start time of the command, the time between

> + * command and response, and the time between response and start of data is

> + * not known, set the command transfer time to 10ms.

> + */

> +#define MMC_CMD_TRANSFER_TIME	(10 * NSEC_PER_MSEC) /* max 10 ms */

> +

>  enum sdhci_cookie {

>  	COOKIE_UNMAPPED,

>  	COOKIE_PRE_MAPPED,	/* mapped by sdhci_pre_req() */

> @@ -555,6 +563,8 @@ struct sdhci_host {

>  	/* Host SDMA buffer boundary. */

>  	u32			sdma_boundary;

>  

> +	u64			data_timeout;

> +

>  	unsigned long private[0] ____cacheline_aligned;

>  };

>  

> 


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Patch

diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index c432ec3644aa..1ed0b8b6570a 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -738,6 +738,39 @@  static unsigned int sdhci_target_timeout(struct sdhci_host *host,
 	return target_timeout;
 }
 
+static void sdhci_calc_sw_timeout(struct sdhci_host *host,
+				  struct mmc_command *cmd)
+{
+	struct mmc_data *data = cmd->data;
+	struct mmc_host *mmc = host->mmc;
+	struct mmc_ios *ios = &mmc->ios;
+	unsigned char bus_width = 1 << ios->bus_width;
+	unsigned int blksz;
+	unsigned int freq;
+	u64 target_timeout;
+	u64 transfer_time;
+
+	target_timeout = sdhci_target_timeout(host, cmd, data);
+	target_timeout *= NSEC_PER_USEC;
+
+	if (data) {
+		blksz = data->blksz;
+		freq = host->mmc->actual_clock ? : host->clock;
+		transfer_time = (u64)blksz * NSEC_PER_SEC * (8 / bus_width);
+		do_div(transfer_time, freq);
+		/* multiply by '2' to account for any unknowns */
+		transfer_time = transfer_time * 2;
+		/* calculate timeout for the entire data */
+		host->data_timeout = data->blocks * target_timeout +
+				     transfer_time;
+	} else {
+		host->data_timeout = target_timeout;
+	}
+
+	if (host->data_timeout)
+		host->data_timeout += MMC_CMD_TRANSFER_TIME;
+}
+
 static u8 sdhci_calc_timeout(struct sdhci_host *host, struct mmc_command *cmd,
 			     bool *too_big)
 {
@@ -831,6 +864,7 @@  static void sdhci_set_timeout(struct sdhci_host *host, struct mmc_command *cmd)
 
 		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);
@@ -845,6 +879,8 @@  static void sdhci_prepare_data(struct sdhci_host *host, struct mmc_command *cmd)
 	u8 ctrl;
 	struct mmc_data *data = cmd->data;
 
+	host->data_timeout = 0;
+
 	if (sdhci_data_line_cmd(cmd))
 		sdhci_set_timeout(host, cmd);
 
diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h
index f6555c0f4ad3..23966f887da6 100644
--- a/drivers/mmc/host/sdhci.h
+++ b/drivers/mmc/host/sdhci.h
@@ -332,6 +332,14 @@  struct sdhci_adma2_64_desc {
 /* Allow for a a command request and a data request at the same time */
 #define SDHCI_MAX_MRQS		2
 
+/*
+ * 48bit command and 136 bit response in 100KHz clock could take upto 2.48ms.
+ * However since the start time of the command, the time between
+ * command and response, and the time between response and start of data is
+ * not known, set the command transfer time to 10ms.
+ */
+#define MMC_CMD_TRANSFER_TIME	(10 * NSEC_PER_MSEC) /* max 10 ms */
+
 enum sdhci_cookie {
 	COOKIE_UNMAPPED,
 	COOKIE_PRE_MAPPED,	/* mapped by sdhci_pre_req() */
@@ -555,6 +563,8 @@  struct sdhci_host {
 	/* Host SDMA buffer boundary. */
 	u32			sdma_boundary;
 
+	u64			data_timeout;
+
 	unsigned long private[0] ____cacheline_aligned;
 };