Merge pull request #36 from grigorig/sdhci-perf-cleanup

sdhci-bcm2708 performance, compatibility and reliability improvements

drivers/mmc/card/block.c

@@ -1492,6 +1492,14 @@ static const struct mmc_fixup blk_fixups[] =
 		  MMC_QUIRK_BLK_NO_CMD23),
 	MMC_FIXUP("MMC32G", 0x11, CID_OEMID_ANY, add_quirk_mmc,
 		  MMC_QUIRK_BLK_NO_CMD23),
+
+	/*
+	 * Some Micron MMC cards needs longer data read timeout than
+	 * indicated in CSD.
+	 */
+	MMC_FIXUP(CID_NAME_ANY, 0x13, 0x200, add_quirk_mmc,
+		  MMC_QUIRK_LONG_READ_TIME),
+
 	END_FIXUP
 };
 

drivers/mmc/core/core.c

@@ -396,10 +396,14 @@ void mmc_set_data_timeout(struct mmc_data *data, const struct mmc_card *card)
 
 		if (data->flags & MMC_DATA_WRITE)
 			/*
-			 * The limit is really 250 ms, but that is
-			 * insufficient for some crappy cards.
+			 * The MMC spec "It is strongly recommended
+			 * for hosts to implement more than 500ms
+			 * timeout value even if the card indicates
+			 * the 250ms maximum busy length."  Even the
+			 * previous value of 300ms is known to be
+			 * insufficient for some cards.
 			 */
-			limit_us = 300000;
+			limit_us = 3000000;
 		else
 			limit_us = 100000;
 
@@ -411,6 +415,18 @@ void mmc_set_data_timeout(struct mmc_data *data, const struct mmc_card *card)
 			data->timeout_clks = 0;
 		}
 	}
+
+	/*
+	 * Some cards require longer data read timeout than indicated in CSD.
+	 * Address this by setting the read timeout to a "reasonably high"
+	 * value. For the cards tested, 300ms has proven enough. If necessary,
+	 * this value can be increased if other problematic cards require this.
+	 */
+	if (mmc_card_long_read_time(card) && data->flags & MMC_DATA_READ) {
+		data->timeout_ns = 300000000;
+		data->timeout_clks = 0;
+	}
+
 	/*
 	 * Some cards need very high timeouts if driven in SPI mode.
 	 * The worst observed timeout was 900ms after writing a
@@ -1119,13 +1135,11 @@ static void mmc_power_up(struct mmc_host *host)
 		bit = fls(host->ocr_avail) - 1;
 
 	host->ios.vdd = bit;
-	if (mmc_host_is_spi(host)) {
+	if (mmc_host_is_spi(host))
 		host->ios.chip_select = MMC_CS_HIGH;
-		host->ios.bus_mode = MMC_BUSMODE_PUSHPULL;
-	} else {
+	else
 		host->ios.chip_select = MMC_CS_DONTCARE;
-		host->ios.bus_mode = MMC_BUSMODE_OPENDRAIN;
-	}
+	host->ios.bus_mode = MMC_BUSMODE_PUSHPULL;
 	host->ios.power_mode = MMC_POWER_UP;
 	host->ios.bus_width = MMC_BUS_WIDTH_1;
 	host->ios.timing = MMC_TIMING_LEGACY;

drivers/mmc/core/mmc.c

@@ -550,6 +550,10 @@ static int mmc_init_card(struct mmc_host *host, u32 ocr,
 	BUG_ON(!host);
 	WARN_ON(!host->claimed);
 
+	/* Set correct bus mode for MMC before attempting init */
+	if (!mmc_host_is_spi(host))
+		mmc_set_bus_mode(host, MMC_BUSMODE_OPENDRAIN);
+
 	/*
 	 * Since we're changing the OCR value, we seem to
 	 * need to tell some cards to go back to the idle
@@ -1019,6 +1023,10 @@ int mmc_attach_mmc(struct mmc_host *host)
 	BUG_ON(!host);
 	WARN_ON(!host->claimed);
 
+	/* Set correct bus mode for MMC before attempting attach */
+	if (!mmc_host_is_spi(host))
+		mmc_set_bus_mode(host, MMC_BUSMODE_OPENDRAIN);
+
 	err = mmc_send_op_cond(host, 0, &ocr);
 	if (err)
 		return err;

drivers/mmc/core/sd.c

@@ -306,6 +306,9 @@ static int mmc_read_switch(struct mmc_card *card)
 		goto out;
 	}
 
+	if (status[13] & UHS_SDR50_BUS_SPEED)
+		card->sw_caps.hs_max_dtr = 50000000;
+
 	if (card->scr.sda_spec3) {
 		card->sw_caps.sd3_bus_mode = status[13];
 
@@ -348,9 +351,6 @@ static int mmc_read_switch(struct mmc_card *card)
 		}
 
 		card->sw_caps.sd3_curr_limit = status[7];
-	} else {
-		if (status[13] & 0x02)
-			card->sw_caps.hs_max_dtr = 50000000;
 	}
 
 out:
@@ -929,8 +929,6 @@ static int mmc_sd_init_card(struct mmc_host *host, u32 ocr,
 		err = mmc_send_relative_addr(host, &card->rca);
 		if (err)
 			return err;
-
-		mmc_set_bus_mode(host, MMC_BUSMODE_PUSHPULL);
 	}
 
 	if (!oldcard) {

drivers/mmc/core/sdio.c

@@ -408,8 +408,6 @@ static int mmc_sdio_init_card(struct mmc_host *host, u32 ocr,
 		 */
 		if (oldcard)
 			oldcard->rca = card->rca;
-
-		mmc_set_bus_mode(host, MMC_BUSMODE_PUSHPULL);
 	}
 
 	/*

drivers/mmc/host/sdhci-bcm2708.c

@@ -74,7 +74,7 @@
 #define BCM2708_SDHCI_SLEEP_TIMEOUT 1000   /* msecs */
 
 /* Mhz clock that the EMMC core is running at. Should match the platform clockman settings */
-#define BCM2708_EMMC_CLOCK_FREQ 80000000
+#define BCM2708_EMMC_CLOCK_FREQ 50000000
 
 #define POWER_OFF 0
 #define POWER_LAZY_OFF 1
@@ -135,6 +135,8 @@ static inline unsigned long int since_ns(hptime_t t)
 	return (unsigned long)((hptime() - t) * HPTIME_CLK_NS);
 }
 
+static bool allow_highspeed = 1;
+
 #if 0
 static void hptime_test(void)
 {
@@ -359,68 +361,9 @@ void sdhci_bcm2708_writeb(struct sdhci_host *host, u8 val, int reg)
 
 static unsigned int sdhci_bcm2708_get_max_clock(struct sdhci_host *host)
 {
-	return 20000000;	// this value is in Hz (20MHz)
-}
-
-static unsigned int sdhci_bcm2708_get_timeout_clock(struct sdhci_host *host)
-{
-	if(host->clock)
-		return (host->clock / 1000);		// this value is in kHz (100MHz)
-	else
-		return (sdhci_bcm2708_get_max_clock(host) / 1000);
+	return BCM2708_EMMC_CLOCK_FREQ;
 }
 
-static void sdhci_bcm2708_set_clock(struct sdhci_host *host, unsigned int clock)
-{
-	int div = 0;
-	u16 clk = 0;
-	unsigned long timeout;
-
-        if (clock == host->clock)
-                return;
-
-        sdhci_writew(host, 0, SDHCI_CLOCK_CONTROL);
-
-        if (clock == 0)
-                goto out;
-
-	if (BCM2708_EMMC_CLOCK_FREQ <= clock)
-		div = 1;
-	else {
-		for (div = 2; div < SDHCI_MAX_DIV_SPEC_300; div += 2) {
-			if ((BCM2708_EMMC_CLOCK_FREQ / div) <= clock)
-				break;
-		}
-	}
-
-        DBG( "desired SD clock: %d, actual: %d\n",
-                clock, BCM2708_EMMC_CLOCK_FREQ / div);
-
-	clk |= (div & SDHCI_DIV_MASK) << SDHCI_DIVIDER_SHIFT;
-	clk |= ((div & SDHCI_DIV_HI_MASK) >> SDHCI_DIV_MASK_LEN)
-		<< SDHCI_DIVIDER_HI_SHIFT;
-	clk |= SDHCI_CLOCK_INT_EN;
-
-	sdhci_writew(host, clk, SDHCI_CLOCK_CONTROL);
-
-        timeout = 20;
-        while (!((clk = sdhci_readw(host, SDHCI_CLOCK_CONTROL))
-                        & SDHCI_CLOCK_INT_STABLE)) {
-                if (timeout == 0) {
-			printk(KERN_ERR "%s: Internal clock never "
-				"stabilised.\n", mmc_hostname(host->mmc));
-                        return;
-                }
-                timeout--;
-                mdelay(1);
-        }
-
-        clk |= SDHCI_CLOCK_CARD_EN;
-        sdhci_writew(host, clk, SDHCI_CLOCK_CONTROL);
-out:
-        host->clock = clock;
- }
-
 /*****************************************************************************\
  *									     *
  * DMA Operation							     *
@@ -907,7 +850,7 @@ static void sdhci_bcm2708_dma_complete_irq(struct sdhci_host *host,
 		while (0 != (sdhci_bcm2708_raw_readl(host, SDHCI_PRESENT_STATE) 
 			& state_mask) && --timeout > 0)
 		{
-			udelay(100);
+			udelay(30);
 			continue;
 		}
 		if (timeout <= 0)
@@ -1307,11 +1250,7 @@ static struct sdhci_ops sdhci_bcm2708_ops = {
 #else
 #error The BCM2708 SDHCI driver needs CONFIG_MMC_SDHCI_IO_ACCESSORS to be set
 #endif
-	//.enable_dma = NULL,
-	.set_clock = sdhci_bcm2708_set_clock,
 	.get_max_clock = sdhci_bcm2708_get_max_clock,
-	//.get_min_clock = NULL,
-	.get_timeout_clock = sdhci_bcm2708_get_timeout_clock,
 
 	.enable = sdhci_bcm2708_enable,
 	.disable = sdhci_bcm2708_disable,
@@ -1374,7 +1313,9 @@ static int __devinit sdhci_bcm2708_probe(struct platform_device *pdev)
 	host->quirks = SDHCI_QUIRK_BROKEN_CARD_DETECTION |
 		       SDHCI_QUIRK_DATA_TIMEOUT_USES_SDCLK |
 		       SDHCI_QUIRK_BROKEN_TIMEOUT_VAL |
-		       SDHCI_QUIRK_NONSTANDARD_CLOCK;
+               SDHCI_QUIRK_MISSING_CAPS |
+               SDHCI_QUIRK_NO_HISPD_BIT;
+
 #ifdef CONFIG_MMC_SDHCI_BCM2708_DMA
 	host->flags = SDHCI_USE_PLATDMA;
 #endif
@@ -1442,7 +1383,8 @@ static int __devinit sdhci_bcm2708_probe(struct platform_device *pdev)
 	    host_priv->dma_chan, host_priv->dma_chan_base,
 	    host_priv->dma_irq);
 
-	host->mmc->caps |= MMC_CAP_SD_HIGHSPEED | MMC_CAP_MMC_HIGHSPEED;
+    if (allow_highspeed)
+        host->mmc->caps |= MMC_CAP_SD_HIGHSPEED | MMC_CAP_MMC_HIGHSPEED;
 #endif
 
 	ret = sdhci_add_host(host);
@@ -1548,8 +1490,12 @@ static void __exit sdhci_drv_exit(void)
 module_init(sdhci_drv_init);
 module_exit(sdhci_drv_exit);
 
+module_param(allow_highspeed, bool, 0444);
+
 MODULE_DESCRIPTION("Secure Digital Host Controller Interface platform driver");
 MODULE_AUTHOR("Broadcom <info@broadcom.com>");
 MODULE_LICENSE("GPL v2");
 MODULE_ALIAS("platform:"DRIVER_NAME);
 
+MODULE_PARM_DESC(allow_highspeed, "Allow high speed transfers modes");
+

include/linux/mmc/card.h

@@ -188,6 +188,7 @@ struct mmc_card {
 #define MMC_QUIRK_DISABLE_CD	(1<<5)		/* disconnect CD/DAT[3] resistor */
 #define MMC_QUIRK_INAND_CMD38	(1<<6)		/* iNAND devices have broken CMD38 */
 #define MMC_QUIRK_BLK_NO_CMD23	(1<<7)		/* Avoid CMD23 for regular multiblock */
+#define MMC_QUIRK_LONG_READ_TIME (1<<9)		/* Data read time > CSD says */
 
 	unsigned int		erase_size;	/* erase size in sectors */
  	unsigned int		erase_shift;	/* if erase unit is power 2 */
@@ -377,6 +378,11 @@ static inline int mmc_card_nonstd_func_interface(const struct mmc_card *c)
 	return c->quirks & MMC_QUIRK_NONSTD_FUNC_IF;
 }
 
+static inline int mmc_card_long_read_time(const struct mmc_card *c)
+{
+	return c->quirks & MMC_QUIRK_LONG_READ_TIME;
+}
+
 #define mmc_card_name(c)	((c)->cid.prod_name)
 #define mmc_card_id(c)		(dev_name(&(c)->dev))