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authorNishanth Menon <nm@ti.com>2010-11-19 11:18:12 -0500
committerSandeep Paulraj <s-paulraj@ti.com>2010-11-19 16:27:37 -0500
commiteb9a28f699667919bf140bdabdf37c25be725c79 (patch)
tree2ba25ba5964c433e270c78acfd5ccdb8862a05c3
parentf35d61ac3d1fd324a171904f3fa114e3b10e24ef (diff)
downloadu-boot-linaro-stable-eb9a28f699667919bf140bdabdf37c25be725c79.tar.gz
mmc: omap: timeout counter fix
Having a loop with a counter is no timing guarentee for timing accuracy or compiler optimizations. For e.g. the same loop counter which runs when the MPU is running at 600MHz will timeout in around half the time when running at 1GHz. or the example where GCC 4.5 compiles with different optimization compared to GCC 4.4. use timer to keep track of time elapse and we use an emperical number - 1sec for a worst case timeout. This should never happen, and is adequate imaginary condition for us to fail with timeout. Signed-off-by: Nishanth Menon <nm@ti.com> Signed-off-by: Sandeep Paulraj <s-paulraj@ti.com>
-rw-r--r--drivers/mmc/omap_hsmmc.c107
1 files changed, 82 insertions, 25 deletions
diff --git a/drivers/mmc/omap_hsmmc.c b/drivers/mmc/omap_hsmmc.c
index c7f76209f..6f2280abf 100644
--- a/drivers/mmc/omap_hsmmc.c
+++ b/drivers/mmc/omap_hsmmc.c
@@ -31,6 +31,9 @@
#include <asm/io.h>
#include <asm/arch/mmc_host_def.h>
+/* If we fail after 1 second wait, something is really bad */
+#define MAX_RETRY_MS 1000
+
static int mmc_read_data(hsmmc_t *mmc_base, char *buf, unsigned int size);
static int mmc_write_data(hsmmc_t *mmc_base, const char *buf, unsigned int siz);
static struct mmc hsmmc_dev[2];
@@ -70,18 +73,29 @@ unsigned char mmc_board_init(hsmmc_t *mmc_base)
void mmc_init_stream(hsmmc_t *mmc_base)
{
+ ulong start;
writel(readl(&mmc_base->con) | INIT_INITSTREAM, &mmc_base->con);
writel(MMC_CMD0, &mmc_base->cmd);
- while (!(readl(&mmc_base->stat) & CC_MASK))
- ;
+ start = get_timer(0);
+ while (!(readl(&mmc_base->stat) & CC_MASK)) {
+ if (get_timer(0) - start > MAX_RETRY_MS) {
+ printf("%s: timedout waiting for cc!\n", __func__);
+ return;
+ }
+ }
writel(CC_MASK, &mmc_base->stat)
;
writel(MMC_CMD0, &mmc_base->cmd)
;
- while (!(readl(&mmc_base->stat) & CC_MASK))
- ;
+ start = get_timer(0);
+ while (!(readl(&mmc_base->stat) & CC_MASK)) {
+ if (get_timer(0) - start > MAX_RETRY_MS) {
+ printf("%s: timedout waiting for cc2!\n", __func__);
+ return;
+ }
+ }
writel(readl(&mmc_base->con) & ~INIT_INITSTREAM, &mmc_base->con);
}
@@ -91,16 +105,28 @@ static int mmc_init_setup(struct mmc *mmc)
hsmmc_t *mmc_base = (hsmmc_t *)mmc->priv;
unsigned int reg_val;
unsigned int dsor;
+ ulong start;
mmc_board_init(mmc_base);
writel(readl(&mmc_base->sysconfig) | MMC_SOFTRESET,
&mmc_base->sysconfig);
- while ((readl(&mmc_base->sysstatus) & RESETDONE) == 0)
- ;
+ start = get_timer(0);
+ while ((readl(&mmc_base->sysstatus) & RESETDONE) == 0) {
+ if (get_timer(0) - start > MAX_RETRY_MS) {
+ printf("%s: timedout waiting for cc2!\n", __func__);
+ return TIMEOUT;
+ }
+ }
writel(readl(&mmc_base->sysctl) | SOFTRESETALL, &mmc_base->sysctl);
- while ((readl(&mmc_base->sysctl) & SOFTRESETALL) != 0x0)
- ;
+ start = get_timer(0);
+ while ((readl(&mmc_base->sysctl) & SOFTRESETALL) != 0x0) {
+ if (get_timer(0) - start > MAX_RETRY_MS) {
+ printf("%s: timedout waiting for softresetall!\n",
+ __func__);
+ return TIMEOUT;
+ }
+ }
writel(DTW_1_BITMODE | SDBP_PWROFF | SDVS_3V0, &mmc_base->hctl);
writel(readl(&mmc_base->capa) | VS30_3V0SUP | VS18_1V8SUP,
&mmc_base->capa);
@@ -116,8 +142,13 @@ static int mmc_init_setup(struct mmc *mmc)
(ICE_STOP | DTO_15THDTO | CEN_DISABLE));
mmc_reg_out(&mmc_base->sysctl, ICE_MASK | CLKD_MASK,
(dsor << CLKD_OFFSET) | ICE_OSCILLATE);
- while ((readl(&mmc_base->sysctl) & ICS_MASK) == ICS_NOTREADY)
- ;
+ start = get_timer(0);
+ while ((readl(&mmc_base->sysctl) & ICS_MASK) == ICS_NOTREADY) {
+ if (get_timer(0) - start > MAX_RETRY_MS) {
+ printf("%s: timedout waiting for ics!\n", __func__);
+ return TIMEOUT;
+ }
+ }
writel(readl(&mmc_base->sysctl) | CEN_ENABLE, &mmc_base->sysctl);
writel(readl(&mmc_base->hctl) | SDBP_PWRON, &mmc_base->hctl);
@@ -137,14 +168,23 @@ static int mmc_send_cmd(struct mmc *mmc, struct mmc_cmd *cmd,
{
hsmmc_t *mmc_base = (hsmmc_t *)mmc->priv;
unsigned int flags, mmc_stat;
- unsigned int retry = 0x100000;
+ ulong start;
-
- while ((readl(&mmc_base->pstate) & DATI_MASK) == DATI_CMDDIS)
- ;
+ start = get_timer(0);
+ while ((readl(&mmc_base->pstate) & DATI_MASK) == DATI_CMDDIS) {
+ if (get_timer(0) - start > MAX_RETRY_MS) {
+ printf("%s: timedout waiting for cmddis!\n", __func__);
+ return TIMEOUT;
+ }
+ }
writel(0xFFFFFFFF, &mmc_base->stat);
- while (readl(&mmc_base->stat))
- ;
+ start = get_timer(0);
+ while (readl(&mmc_base->stat)) {
+ if (get_timer(0) - start > MAX_RETRY_MS) {
+ printf("%s: timedout waiting for stat!\n", __func__);
+ return TIMEOUT;
+ }
+ }
/*
* CMDREG
* CMDIDX[13:8] : Command index
@@ -200,15 +240,14 @@ static int mmc_send_cmd(struct mmc *mmc, struct mmc_cmd *cmd,
writel(cmd->cmdarg, &mmc_base->arg);
writel((cmd->cmdidx << 24) | flags, &mmc_base->cmd);
+ start = get_timer(0);
do {
mmc_stat = readl(&mmc_base->stat);
- retry--;
- } while ((mmc_stat == 0) && (retry > 0));
-
- if (retry == 0) {
- printf("%s : timeout: No status update\n", __func__);
- return TIMEOUT;
- }
+ if (get_timer(0) - start > MAX_RETRY_MS) {
+ printf("%s : timeout: No status update\n", __func__);
+ return TIMEOUT;
+ }
+ } while (!mmc_stat);
if ((mmc_stat & IE_CTO) != 0)
return TIMEOUT;
@@ -253,8 +292,14 @@ static int mmc_read_data(hsmmc_t *mmc_base, char *buf, unsigned int size)
count /= 4;
while (size) {
+ ulong start = get_timer(0);
do {
mmc_stat = readl(&mmc_base->stat);
+ if (get_timer(0) - start > MAX_RETRY_MS) {
+ printf("%s: timedout waiting for status!\n",
+ __func__);
+ return TIMEOUT;
+ }
} while (mmc_stat == 0);
if ((mmc_stat & ERRI_MASK) != 0)
@@ -298,8 +343,14 @@ static int mmc_write_data(hsmmc_t *mmc_base, const char *buf, unsigned int size)
count /= 4;
while (size) {
+ ulong start = get_timer(0);
do {
mmc_stat = readl(&mmc_base->stat);
+ if (get_timer(0) - start > MAX_RETRY_MS) {
+ printf("%s: timedout waiting for status!\n",
+ __func__);
+ return TIMEOUT;
+ }
} while (mmc_stat == 0);
if ((mmc_stat & ERRI_MASK) != 0)
@@ -334,6 +385,7 @@ static void mmc_set_ios(struct mmc *mmc)
{
hsmmc_t *mmc_base = (hsmmc_t *)mmc->priv;
unsigned int dsor = 0;
+ ulong start;
/* configue bus width */
switch (mmc->bus_width) {
@@ -372,8 +424,13 @@ static void mmc_set_ios(struct mmc *mmc)
mmc_reg_out(&mmc_base->sysctl, ICE_MASK | CLKD_MASK,
(dsor << CLKD_OFFSET) | ICE_OSCILLATE);
- while ((readl(&mmc_base->sysctl) & ICS_MASK) == ICS_NOTREADY)
- ;
+ start = get_timer(0);
+ while ((readl(&mmc_base->sysctl) & ICS_MASK) == ICS_NOTREADY) {
+ if (get_timer(0) - start > MAX_RETRY_MS) {
+ printf("%s: timedout waiting for ics!\n", __func__);
+ return;
+ }
+ }
writel(readl(&mmc_base->sysctl) | CEN_ENABLE, &mmc_base->sysctl);
}