[PATCH V3 29/30] omap_hsmmc: set a large data timeout for commands with busy signal

Adrian Hunter
2009-09-09T12:00:10Z

>From c85a80da2efe181ff256074f7bcd9099428f2572 Mon Sep 17 00:00:00 2001
From: Adrian Hunter <adrian.hunter@nokia.com>
Date: Fri, 26 Jun 2009 11:29:20 +0300
Subject: [PATCH] omap_hsmmc: set a large data timeout for commands with busy signal

Commands like SWITCH (CMD6) send a response and then signal busy
while the operation is completed. These commands are expected
to always succeed (otherwise the response would have indicated an
error).

Set an arbitrarily large data timeout value (100ms) for these commands
to ensure that premature timeouts do not occur.

Signed-off-by: Adrian Hunter <adrian.hunter@nokia.com>
---
drivers/mmc/host/omap_hsmmc.c | 15 +++++++++++----
1 files changed, 11 insertions(+), 4 deletions(-)

diff --git a/drivers/mmc/host/omap_hsmmc.c b/drivers/mmc/host/omap_hsmmc.c
index 64780da..b54f3e3 100644
--- a/drivers/mmc/host/omap_hsmmc.c
+++ b/drivers/mmc/host/omap_hsmmc.c
@@ -990,7 +990,8 @@ static int omap_hsmmc_start_dma_transfer(struct omap_hsmmc_host *host,
}

static void set_data_timeout(struct omap_hsmmc_host *host,
- struct mmc_request *req)
+ unsigned int timeout_ns,
+ unsigned int timeout_clks)
{
unsigned int timeout, cycle_ns;
uint32_t reg, clkd, dto = 0;
@@ -1001,8 +1002,8 @@ static void set_data_timeout(struct omap_hsmmc_host *host,
clkd = 1;

cycle_ns = 1000000000 / (clk_get_rate(host->fclk) / clkd);
- timeout = req->data->timeout_ns / cycle_ns;
- timeout += req->data->timeout_clks;
+ timeout = timeout_ns / cycle_ns;
+ timeout += timeout_clks;
if (timeout) {
while ((timeout & 0x80000000) == 0) {
dto += 1;
@@ -1036,12 +1037,18 @@ omap_hsmmc_prepare_data(struct omap_hsmmc_host *host, struct mmc_request *req)

if (req->data == NULL) {
OMAP_HSMMC_WRITE(host->base, BLK, 0);
+ /*
+ * Set an arbitrary 100ms data timeout for commands with
+ * busy signal.
+ */
+ if (req->cmd->flags & MMC_RSP_BUSY)
+ set_data_timeout(host, 100000000U, 0);
return 0;
}

OMAP_HSMMC_WRITE(host->base, BLK, (req->data->blksz)
| (req->data->blocks << 16));
- set_data_timeout(host, req);
+ set_data_timeout(host, req->data->timeout_ns, req->data->timeout_clks);

if (host->use_dma) {
ret = omap_hsmmc_start_dma_transfer(host, req);
--
1.5.6.3