Rather than to poll in a busy-loop, let's convert into using
readl_poll_timeout() and insert a small delay between each polling
attempts. In particular, this avoids hogging the CPU.
Additionally, to convert to readl_poll_timeout() we also need to switch
from using a specific number of polling attempts, into a specific timeout
in us instead. The previous 100000 attempts, is translated into a total
timeout of total 1s, as that seemed like reasonable value to pick.
Cc: Sascha Sommer <saschasommer@xxxxxxxxxx>
Signed-off-by: Ulf Hansson <ulf.hansson@xxxxxxxxxx>
---
drivers/mmc/host/sdricoh_cs.c | 32 +++++++++++++++-----------------
1 file changed, 15 insertions(+), 17 deletions(-)
diff --git a/drivers/mmc/host/sdricoh_cs.c b/drivers/mmc/host/sdricoh_cs.c
index 7e407fb6dab8..d7a191f14337 100644
--- a/drivers/mmc/host/sdricoh_cs.c
+++ b/drivers/mmc/host/sdricoh_cs.c
@@ -59,7 +59,7 @@ static unsigned int switchlocked;
#define STATUS_BUSY 0x40000000
/* timeouts */
-#define CMD_TIMEOUT 100000
+#define SDRICOH_CMD_TIMEOUT_US 1000000
#define SDRICOH_DATA_TIMEOUT_US 1000000
/* list of supported pcmcia devices */
@@ -157,8 +157,7 @@ static int sdricoh_query_status(struct sdricoh_host *host, unsigned int wanted)
static int sdricoh_mmc_cmd(struct sdricoh_host *host, struct mmc_command *cmd)
{
unsigned int status;
- int result = 0;
- unsigned int loop = 0;
+ int ret;
unsigned char opcode = cmd->opcode;
/* reset status reg? */
@@ -174,24 +173,23 @@ static int sdricoh_mmc_cmd(struct sdricoh_host *host, struct mmc_command *cmd)
/* fill parameters */
sdricoh_writel(host, R204_CMD_ARG, cmd->arg);
sdricoh_writel(host, R200_CMD, (0x10000 << 8) | opcode);
+
/* wait for command completion */
- if (opcode) {
- for (loop = 0; loop < CMD_TIMEOUT; loop++) {
- status = sdricoh_readl(host, R21C_STATUS);
- sdricoh_writel(host, R2E4_STATUS_RESP, status);
- if (status & STATUS_CMD_FINISHED)
- break;
- }
- /* don't check for timeout in the loop it is not always
- reset correctly
- */
- if (loop == CMD_TIMEOUT || status & STATUS_CMD_TIMEOUT)
- result = -ETIMEDOUT;
+ if (!opcode)
+ return 0;
- }
+ ret = readl_poll_timeout(host->iobase + R21C_STATUS, status,
+ sdricoh_status_ok(host, status, STATUS_CMD_FINISHED),
+ 32, SDRICOH_CMD_TIMEOUT_US);
- return result;
+ /*
+ * Don't check for timeout status in the loop, as it's not always reset
+ * correctly.
+ */
+ if (ret || status & STATUS_CMD_TIMEOUT)
+ return -ETIMEDOUT;
+ return 0;
}
static int sdricoh_reset(struct sdricoh_host *host)
--
2.20.1
