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openwrt/target/linux/brcm2708/patches-3.10/0038-Lazy-CRC-quirk-Impleme...

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From d94e2bd60b27f2ff7d6e9ff7ee43848bb2090c06 Mon Sep 17 00:00:00 2001
From: dero <de@ro>
Date: Mon, 19 Nov 2012 12:46:06 +0100
Subject: [PATCH 038/196] Lazy CRC quirk: Implemented retrying mechanisms for
SD SSR and SCR, disabled missing_status and spurious CRC ACMD51 quirks by
default (should be fixed by the retrying-mechanishm)
---
drivers/mmc/core/sd.c | 115 +++++++++++++++++++++++++++++++++------
drivers/mmc/host/sdhci-bcm2708.c | 11 +++-
2 files changed, 108 insertions(+), 18 deletions(-)
diff --git a/drivers/mmc/core/sd.c b/drivers/mmc/core/sd.c
index 9e645e1..1ee6cf3 100644
--- a/drivers/mmc/core/sd.c
+++ b/drivers/mmc/core/sd.c
@@ -13,6 +13,8 @@
#include <linux/err.h>
#include <linux/slab.h>
#include <linux/stat.h>
+#include <linux/jiffies.h>
+#include <linux/nmi.h>
#include <linux/mmc/host.h>
#include <linux/mmc/card.h>
@@ -58,6 +60,15 @@ static const unsigned int tacc_mant[] = {
__res & __mask; \
})
+// timeout for tries
+static const unsigned long retry_timeout_ms= 10*1000;
+
+// try at least 10 times, even if timeout is reached
+static const int retry_min_tries= 10;
+
+// delay between tries
+static const unsigned long retry_delay_ms= 10;
+
/*
* Given the decoded CSD structure, decode the raw CID to our CID structure.
*/
@@ -210,12 +221,62 @@ static int mmc_decode_scr(struct mmc_card *card)
}
/*
- * Fetch and process SD Status register.
+ * Fetch and process SD Configuration Register.
+ */
+static int mmc_read_scr(struct mmc_card *card)
+{
+ unsigned long timeout_at;
+ int err, tries;
+
+ timeout_at= jiffies + msecs_to_jiffies( retry_timeout_ms );
+ tries= 0;
+
+ while( tries < retry_min_tries || time_before( jiffies, timeout_at ) )
+ {
+ unsigned long delay_at;
+ tries++;
+
+ err = mmc_app_send_scr(card, card->raw_scr);
+ if( !err )
+ break; // sucess!!!
+
+ touch_nmi_watchdog(); // we are still alive!
+
+ // delay
+ delay_at= jiffies + msecs_to_jiffies( retry_delay_ms );
+ while( time_before( jiffies, delay_at ) )
+ {
+ mdelay( 1 );
+ touch_nmi_watchdog(); // we are still alive!
+ }
+ }
+
+ if( err)
+ {
+ pr_err("%s: failed to read SD Configuration register (SCR) after %d tries during %lu ms, error %d\n", mmc_hostname(card->host), tries, retry_timeout_ms, err );
+ return err;
+ }
+
+ if( tries > 1 )
+ {
+ pr_info("%s: could read SD Configuration register (SCR) at the %dth attempt\n", mmc_hostname(card->host), tries );
+ }
+
+ err = mmc_decode_scr(card);
+ if (err)
+ return err;
+
+ return err;
+}
+
+/*
+ * Fetch and process SD Status Register.
*/
static int mmc_read_ssr(struct mmc_card *card)
{
+ unsigned long timeout_at;
unsigned int au, es, et, eo;
- int err, i;
+ int err, i, tries;
u32 *ssr;
if (!(card->csd.cmdclass & CCC_APP_SPEC)) {
@@ -227,15 +288,41 @@ static int mmc_read_ssr(struct mmc_card *card)
ssr = kmalloc(64, GFP_KERNEL);
if (!ssr)
return -ENOMEM;
-
- err = mmc_app_sd_status(card, ssr);
- if (err) {
- pr_warning("%s: problem reading SD Status "
- "register.\n", mmc_hostname(card->host));
- err = 0;
+
+ timeout_at= jiffies + msecs_to_jiffies( retry_timeout_ms );
+ tries= 0;
+
+ while( tries < retry_min_tries || time_before( jiffies, timeout_at ) )
+ {
+ unsigned long delay_at;
+ tries++;
+
+ err= mmc_app_sd_status(card, ssr);
+ if( !err )
+ break; // sucess!!!
+
+ touch_nmi_watchdog(); // we are still alive!
+
+ // delay
+ delay_at= jiffies + msecs_to_jiffies( retry_delay_ms );
+ while( time_before( jiffies, delay_at ) )
+ {
+ mdelay( 1 );
+ touch_nmi_watchdog(); // we are still alive!
+ }
+ }
+
+ if( err)
+ {
+ pr_err("%s: failed to read SD Status register (SSR) after %d tries during %lu ms, error %d\n", mmc_hostname(card->host), tries, retry_timeout_ms, err );
goto out;
}
+ if( tries > 1 )
+ {
+ pr_info("%s: could read SD Status register (SSR) at the %dth attempt\n", mmc_hostname(card->host), tries );
+ }
+
for (i = 0; i < 16; i++)
ssr[i] = be32_to_cpu(ssr[i]);
@@ -808,15 +895,11 @@ int mmc_sd_setup_card(struct mmc_host *host, struct mmc_card *card,
if (!reinit) {
/*
- * Fetch SCR from card.
+ * Fetch and decode SD Configuration register.
*/
- err = mmc_app_send_scr(card, card->raw_scr);
- if (err)
- return err;
-
- err = mmc_decode_scr(card);
- if (err)
- return err;
+ err = mmc_read_scr(card);
+ if( err )
+ return err;
/*
* Fetch and process SD Status register.
diff --git a/drivers/mmc/host/sdhci-bcm2708.c b/drivers/mmc/host/sdhci-bcm2708.c
index ffd7310..3556ed3 100644
--- a/drivers/mmc/host/sdhci-bcm2708.c
+++ b/drivers/mmc/host/sdhci-bcm2708.c
@@ -137,6 +137,7 @@ static bool allow_highspeed = 1;
static int emmc_clock_freq = BCM2708_EMMC_CLOCK_FREQ;
static bool sync_after_dma = 1;
static bool missing_status = 1;
+static bool spurious_crc_acmd51 = 0;
bool enable_llm = 1;
#if 0
@@ -1103,7 +1104,7 @@ static unsigned int sdhci_bcm2708_quirk_extra_ints(struct sdhci_host *host)
return 1;
}
-static unsigned int sdhci_bcm2708_quirk_spurious_crc(struct sdhci_host *host)
+static unsigned int sdhci_bcm2708_quirk_spurious_crc_acmd51(struct sdhci_host *host)
{
return 1;
}
@@ -1149,7 +1150,6 @@ static struct sdhci_ops sdhci_bcm2708_ops = {
.pdma_reset = sdhci_bcm2708_platdma_reset,
#endif
.extra_ints = sdhci_bcm2708_quirk_extra_ints,
- .spurious_crc_acmd51 = sdhci_bcm2708_quirk_spurious_crc,
.voltage_broken = sdhci_bcm2708_quirk_voltage_broken,
.uhs_broken = sdhci_bcm2708_uhs_broken,
};
@@ -1194,6 +1194,11 @@ static int sdhci_bcm2708_probe(struct platform_device *pdev)
sdhci_bcm2708_ops.missing_status = sdhci_bcm2708_missing_status;
}
+ if( spurious_crc_acmd51 ) {
+ sdhci_bcm2708_ops.spurious_crc_acmd51 = sdhci_bcm2708_quirk_spurious_crc_acmd51;
+ }
+
+
printk("sdhci: %s low-latency mode\n",enable_llm?"Enable":"Disable");
host->hw_name = "BCM2708_Arasan";
@@ -1389,6 +1394,7 @@ module_param(allow_highspeed, bool, 0444);
module_param(emmc_clock_freq, int, 0444);
module_param(sync_after_dma, bool, 0444);
module_param(missing_status, bool, 0444);
+module_param(spurious_crc_acmd51, bool, 0444);
module_param(enable_llm, bool, 0444);
module_param(cycle_delay, int, 0444);
@@ -1401,6 +1407,7 @@ MODULE_PARM_DESC(allow_highspeed, "Allow high speed transfers modes");
MODULE_PARM_DESC(emmc_clock_freq, "Specify the speed of emmc clock");
MODULE_PARM_DESC(sync_after_dma, "Block in driver until dma complete");
MODULE_PARM_DESC(missing_status, "Use the missing status quirk");
+MODULE_PARM_DESC(spurious_crc_acmd51, "Use the spurious crc quirk for reading SCR (ACMD51)");
MODULE_PARM_DESC(enable_llm, "Enable low-latency mode");
--
1.9.1
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