1 files changed, 292 insertions, 0 deletions
diff --git a/target/linux/brcm2708/patches-4.1/0092-bcm2835-sdhost-Further-improve-overclock-back-off.patch b/target/linux/brcm2708/patches-4.1/0092-bcm2835-sdhost-Further-improve-overclock-back-off.patch
new file mode 100644
index 0000000..2005627
--- /dev/null
+++ b/target/linux/brcm2708/patches-4.1/0092-bcm2835-sdhost-Further-improve-overclock-back-off.patch
@@ -0,0 +1,292 @@
+From 8509eb475ed00c7d581cf05866a27fa48c4c007c Mon Sep 17 00:00:00 2001
+From: Phil Elwell <phil@raspberrypi.org>
+Date: Thu, 25 Jun 2015 08:47:09 +0100
+Subject: [PATCH 092/203] bcm2835-sdhost: Further improve overclock back-off
+
+---
+ drivers/mmc/host/bcm2835-sdhost.c | 144 +++++++++++++++++++++-----------------
+ 1 file changed, 78 insertions(+), 66 deletions(-)
+
+--- a/drivers/mmc/host/bcm2835-sdhost.c
++++ b/drivers/mmc/host/bcm2835-sdhost.c
+@@ -161,8 +161,6 @@ struct bcm2835_host {
+ 
+ 	unsigned int			use_busy:1;		/* Wait for busy interrupt */
+ 
+-	unsigned int			reduce_overclock:1;	/* ...at the next opportunity */
+-
+ 	unsigned int			debug:1;		/* Enable debug output */
+ 
+ 	u32				thread_isr;
+@@ -466,36 +464,25 @@ static void bcm2835_sdhost_dma_complete(
+ 	spin_unlock_irqrestore(&host->lock, flags);
+ }
+ 
+-static bool data_transfer_wait(struct bcm2835_host *host, const char *caller)
++static bool data_transfer_wait(struct bcm2835_host *host)
+ {
+ 	unsigned long timeout = 1000000;
+-	u32 hsts;
+ 	while (timeout)
+ 	{
+-		hsts = bcm2835_sdhost_read(host, SDHSTS);
+-		if (hsts & (SDHSTS_TRANSFER_ERROR_MASK |
+-			    SDHSTS_DATA_FLAG)) {
+-			bcm2835_sdhost_write(host, SDHSTS_TRANSFER_ERROR_MASK,
+-					     SDHSTS);
++		u32 sdhsts = bcm2835_sdhost_read(host, SDHSTS);
++		if (sdhsts & SDHSTS_DATA_FLAG) {
++			bcm2835_sdhost_write(host, SDHSTS_DATA_FLAG, SDHSTS);
+ 			break;
+ 		}
+ 		timeout--;
+ 	}
+-
+-	if (hsts & (SDHSTS_CRC16_ERROR |
+-		    SDHSTS_CRC7_ERROR |
+-		    SDHSTS_FIFO_ERROR)) {
+-		pr_err("%s: data error in %s - HSTS %x\n",
+-		       mmc_hostname(host->mmc), caller, hsts);
+-		host->data->error = -EILSEQ;
+-		return false;
+-	} else if ((timeout == 0) ||
+-		   (hsts & (SDHSTS_CMD_TIME_OUT |
+-			    SDHSTS_REW_TIME_OUT))) {
+-		pr_err("%s: timeout in %s - HSTS %x\n",
+-		       mmc_hostname(host->mmc), caller, hsts);
+-		host->data->error = -ETIMEDOUT;
+-		return false;
++	if (timeout == 0) {
++	    pr_err("%s: Data %s timeout\n",
++		   mmc_hostname(host->mmc),
++		   (host->data->flags & MMC_DATA_READ) ? "read" : "write");
++	    bcm2835_sdhost_dumpregs(host);
++	    host->data->error = -ETIMEDOUT;
++	    return false;
+ 	}
+ 	return true;
+ }
+@@ -523,7 +510,7 @@ static void bcm2835_sdhost_read_block_pi
+ 		buf = (u32 *)host->sg_miter.addr;
+ 
+ 		while (len) {
+-			if (!data_transfer_wait(host, "read_block_pio"))
++			if (!data_transfer_wait(host))
+ 				break;
+ 
+ 			*(buf++) = bcm2835_sdhost_read(host, SDDATA);
+@@ -562,7 +549,7 @@ static void bcm2835_sdhost_write_block_p
+ 		buf = host->sg_miter.addr;
+ 
+ 		while (len) {
+-			if (!data_transfer_wait(host, "write_block_pio"))
++			if (!data_transfer_wait(host))
+ 				break;
+ 
+ 			bcm2835_sdhost_write(host, *(buf++), SDDATA);
+@@ -581,13 +568,33 @@ static void bcm2835_sdhost_write_block_p
+ 
+ static void bcm2835_sdhost_transfer_pio(struct bcm2835_host *host)
+ {
++	u32 sdhsts;
++	bool is_read;
+ 	BUG_ON(!host->data);
+ 
+-	if (host->data->flags & MMC_DATA_READ) {
++	is_read = (host->data->flags & MMC_DATA_READ) != 0;
++	if (is_read)
+ 		bcm2835_sdhost_read_block_pio(host);
+-	} else {
++	else
+ 		bcm2835_sdhost_write_block_pio(host);
+ 
++	sdhsts = bcm2835_sdhost_read(host, SDHSTS);
++	if (sdhsts & (SDHSTS_CRC16_ERROR |
++		      SDHSTS_CRC7_ERROR |
++		      SDHSTS_FIFO_ERROR)) {
++		pr_err("%s: %s transfer error - HSTS %x\n",
++		       mmc_hostname(host->mmc),
++		       is_read ? "read" : "write",
++		       sdhsts);
++		host->data->error = -EILSEQ;
++	} else if ((sdhsts & (SDHSTS_CMD_TIME_OUT |
++			      SDHSTS_REW_TIME_OUT))) {
++		pr_err("%s: %s timeout error - HSTS %x\n",
++		       mmc_hostname(host->mmc),
++		       is_read ? "read" : "write",
++		       sdhsts);
++		host->data->error = -ETIMEDOUT;
++	} else if (!is_read && !host->data->error) {
+ 		/* Start a timer in case a transfer error occurs because
+ 		   there is no error interrupt */
+ 		mod_timer(&host->pio_timer, jiffies + host->pio_timeout);
+@@ -701,8 +708,9 @@ static void bcm2835_sdhost_prepare_data(
+ 
+ void bcm2835_sdhost_send_command(struct bcm2835_host *host, struct mmc_command *cmd)
+ {
+-	u32 sdcmd;
++	u32 sdcmd, sdhsts;
+ 	unsigned long timeout;
++	int delay;
+ 
+ 	WARN_ON(host->cmd);
+ 
+@@ -719,8 +727,8 @@ void bcm2835_sdhost_send_command(struct
+ 			 mmc_hostname(host->mmc),
+ 			 cmd->opcode, cmd->arg, cmd->flags);
+ 
+-	/* Wait max 10 ms */
+-	timeout = 1000;
++	/* Wait max 100 ms */
++	timeout = 10000;
+ 
+ 	while (bcm2835_sdhost_read(host, SDCMD) & SDCMD_NEW_FLAG) {
+ 		if (timeout == 0) {
+@@ -735,8 +743,9 @@ void bcm2835_sdhost_send_command(struct
+ 		udelay(10);
+ 	}
+ 
+-	if ((1000-timeout)/100 > 1 && (1000-timeout)/100 > host->max_delay) {
+-		host->max_delay = (1000-timeout)/100;
++	delay = (10000 - timeout)/100;
++	if (delay > host->max_delay) {
++		host->max_delay = delay;
+ 		pr_warning("%s: controller hung for %d ms\n",
+ 			   mmc_hostname(host->mmc),
+ 			   host->max_delay);
+@@ -751,6 +760,11 @@ void bcm2835_sdhost_send_command(struct
+ 
+ 	host->cmd = cmd;
+ 
++	/* Clear any error flags */
++	sdhsts = bcm2835_sdhost_read(host, SDHSTS);
++	if (sdhsts & SDHSTS_ERROR_MASK)
++		bcm2835_sdhost_write(host, sdhsts, SDHSTS);
++
+ 	bcm2835_sdhost_prepare_data(host, cmd);
+ 
+ 	bcm2835_sdhost_write(host, cmd->arg, SDARG);
+@@ -876,7 +890,7 @@ static void bcm2835_sdhost_transfer_comp
+ static void bcm2835_sdhost_finish_command(struct bcm2835_host *host)
+ {
+ 	u32 sdcmd;
+-	int timeout = 1000;
++	unsigned long timeout;
+ #ifdef DEBUG
+ 	struct timeval before, after;
+ 	int timediff = 0;
+@@ -889,6 +903,8 @@ static void bcm2835_sdhost_finish_comman
+ #ifdef DEBUG
+ 	do_gettimeofday(&before);
+ #endif
++	/* Wait max 100 ms */
++	timeout = 10000;
+ 	for (sdcmd = bcm2835_sdhost_read(host, SDCMD);
+ 	     (sdcmd & SDCMD_NEW_FLAG) && timeout;
+ 	     timeout--) {
+@@ -1049,9 +1065,9 @@ static void bcm2835_sdhost_pio_timeout(u
+ 	spin_lock_irqsave(&host->lock, flags);
+ 
+ 	if (host->data) {
+-		u32 hsts = bcm2835_sdhost_read(host, SDHSTS);
++		u32 sdhsts = bcm2835_sdhost_read(host, SDHSTS);
+ 
+-		if (hsts & SDHSTS_REW_TIME_OUT) {
++		if (sdhsts & SDHSTS_REW_TIME_OUT) {
+ 			pr_err("%s: transfer timeout\n",
+ 			       mmc_hostname(host->mmc));
+ 			if (host->debug)
+@@ -1380,19 +1396,10 @@ void bcm2835_sdhost_set_clock(struct bcm
+ 	if (host->debug)
+ 		pr_info("%s: set_clock(%d)\n", mmc_hostname(host->mmc), clock);
+ 
+-	if ((clock == 0) && host->reduce_overclock) {
+-		/* This is a reset following data corruption - reduce any
+-		   overclock */
+-		host->reduce_overclock = 0;
+-		if (host->overclock_50 > 50) {
+-			pr_warn("%s: reducing overclock due to errors\n",
+-				mmc_hostname(host->mmc));
+-			host->overclock_50--;
+-		}
+-	}
+-
+-	if (host->overclock_50 && (clock == 50*MHZ))
++	if ((host->overclock_50 > 50) &&
++	    (clock == 50*MHZ)) {
+ 		clock = host->overclock_50 * MHZ + (MHZ - 1);
++	}
+ 
+ 	/* The SDCDIV register has 11 bits, and holds (div - 2).
+ 	   But in data mode the max is 50MHz wihout a minimum, and only the
+@@ -1450,11 +1457,12 @@ void bcm2835_sdhost_set_clock(struct bcm
+ 			host->overclock = clock;
+ 		}
+ 	}
+-	else if ((clock == 50 * MHZ) && host->overclock)
++	else if (host->overclock)
+ 	{
+-		pr_warn("%s: cancelling overclock\n",
+-			mmc_hostname(host->mmc));
+ 		host->overclock = 0;
++		if (clock == 50 * MHZ)
++			pr_warn("%s: cancelling overclock\n",
++				mmc_hostname(host->mmc));
+ 	}
+ 
+ 	host->cdiv = div;
+@@ -1492,6 +1500,14 @@ static void bcm2835_sdhost_request(struc
+ 				cmd->opcode, cmd->arg, cmd->flags);
+ 	}
+ 
++	/* Reset the error statuses in case this is a retry */
++	if (mrq->cmd)
++		mrq->cmd->error = 0;
++	if (mrq->data)
++		mrq->data->error = 0;
++	if (mrq->stop)
++		mrq->stop->error = 0;
++
+ 	if (mrq->data && !is_power_of_2(mrq->data->blksz)) {
+ 		pr_err("%s: unsupported block size (%d bytes)\n",
+ 		       mmc_hostname(mmc), mrq->data->blksz);
+@@ -1613,21 +1629,16 @@ static void bcm2835_sdhost_tasklet_finis
+ 
+ 	/* Drop the overclock after any data corruption, or after any
+ 	   error overclocked */
+-	if (mrq->data && (mrq->data->error == -EILSEQ))
+-		host->reduce_overclock = 1;
+-	else if (host->overclock) {
+-		/* Convert timeout errors while overclocked to data errors,
+-		   because the system recovers better. */
+-		if (mrq->cmd && mrq->cmd->error) {
+-			host->reduce_overclock = 1;
+-			if (mrq->cmd->error == -ETIMEDOUT)
+-				mrq->cmd->error = -EILSEQ;
+-		}
+-
+-		if (mrq->data && mrq->data->error) {
+-			host->reduce_overclock = 1;
+-			if (mrq->data->error == -ETIMEDOUT)
+-				mrq->data->error = -EILSEQ;
++	if (host->overclock) {
++		if ((mrq->cmd && mrq->cmd->error) ||
++		    (mrq->data && mrq->data->error) ||
++		    (mrq->stop && mrq->stop->error)) {
++			host->overclock_50--;
++			pr_warn("%s: reducing overclock due to errors\n",
++				mmc_hostname(host->mmc));
++			bcm2835_sdhost_set_clock(host,50*MHZ);
++			mrq->cmd->error = -EILSEQ;
++			mrq->cmd->retries = 1;
+ 		}
+ 	}
+ 
+@@ -1769,6 +1780,7 @@ static int bcm2835_sdhost_probe(struct p
+ 	host = mmc_priv(mmc);
+ 	host->mmc = mmc;
+ 	host->pio_timeout = msecs_to_jiffies(500);
++	host->max_delay = 1; /* Warn if over 1ms */
+ 	spin_lock_init(&host->lock);
+ 
+ 	iomem = platform_get_resource(pdev, IORESOURCE_MEM, 0);