[PATCH V2] sdhci: always use max timeout for xfers

Philip Rakity
2011-02-25T18:50:11Z

v2

use define for max timeout. remove subroutine call and just
set the register directly

v1

The card/host controller may sometimes return a value that is
too low and cause the h/w to timeout a transfer that would have
worked. Using the maximum value avoids this.

Signed-off-by: Philip Rakity <prakity@marvell.com>
---
drivers/mmc/host/sdhci.c | 59 +++++----------------------------------------
drivers/mmc/host/sdhci.h | 1 +
2 files changed, 8 insertions(+), 52 deletions(-)

diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index 655617c..d615173 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -592,55 +592,6 @@ static void sdhci_adma_table_post(struct sdhci_host *host,
data->sg_len, direction);
}

-static u8 sdhci_calc_timeout(struct sdhci_host *host, struct mmc_data *data)
-{
- u8 count;
- unsigned target_timeout, current_timeout;
-
- /*
- * If the host controller provides us with an incorrect timeout
- * value, just skip the check and use 0xE. The hardware may take
- * longer to time out, but that's much better than having a too-short
- * timeout value.
- */
- if (host->quirks & SDHCI_QUIRK_BROKEN_TIMEOUT_VAL)
- return 0xE;
-
- /* timeout in us */
- target_timeout = data->timeout_ns / 1000 +
- data->timeout_clks / host->clock;
-
- if (host->quirks & SDHCI_QUIRK_DATA_TIMEOUT_USES_SDCLK)
- host->timeout_clk = host->clock / 1000;
-
- /*
- * Figure out needed cycles.
- * We do this in steps in order to fit inside a 32 bit int.
- * The first step is the minimum timeout, which will have a
- * minimum resolution of 6 bits:
- * (1) 2^13*1000 > 2^22,
- * (2) host->timeout_clk < 2^16
- * =>
- * (1) / (2) > 2^6
- */
- count = 0;
- current_timeout = (1 << 13) * 1000 / host->timeout_clk;
- while (current_timeout < target_timeout) {
- count++;
- current_timeout <<= 1;
- if (count >= 0xF)
- break;
- }
-
- if (count >= 0xF) {
- printk(KERN_WARNING "%s: Too large timeout requested!\n",
- mmc_hostname(host->mmc));
- count = 0xE;
- }
-
- return count;
-}
-
static void sdhci_set_transfer_irqs(struct sdhci_host *host)
{
u32 pio_irqs = SDHCI_INT_DATA_AVAIL | SDHCI_INT_SPACE_AVAIL;
@@ -654,7 +605,6 @@ static void sdhci_set_transfer_irqs(struct sdhci_host *host)

static void sdhci_prepare_data(struct sdhci_host *host, struct mmc_data *data)
{
- u8 count;
u8 ctrl;
int ret;

@@ -671,8 +621,13 @@ static void sdhci_prepare_data(struct sdhci_host *host, struct mmc_data *data)
host->data = data;
host->data_early = 0;

- count = sdhci_calc_timeout(host, data);
- sdhci_writeb(host, count, SDHCI_TIMEOUT_CONTROL);
+ /*
+ * The host controller/card can provide us with an incorrect timeout
+ * value, just use the maximum value 0xE. The hardware may take
+ * longer to time out, but that's much better than having a too-short
+ * timeout value.
+ */
+ sdhci_writeb(host, SDHCI_TIMEOUT_MAX, SDHCI_TIMEOUT_CONTROL);

if (host->flags & (SDHCI_USE_SDMA | SDHCI_USE_ADMA))
host->flags |= SDHCI_REQ_USE_DMA;
diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h
index 1f032c0..19b4d41 100644
--- a/drivers/mmc/host/sdhci.h
+++ b/drivers/mmc/host/sdhci.h
@@ -103,6 +103,7 @@
#define SDHCI_CLOCK_INT_EN 0x0001

#define SDHCI_TIMEOUT_CONTROL 0x2E
+#define SDHCI_TIMEOUT_MAX 0xE

#define SDHCI_SOFTWARE_RESET 0x2F
#define SDHCI_RESET_ALL 0x01
--
1.7.0.4