diff options
| author | Olivier Sobrie <olivier@sobrie.be> | 2012-03-26 21:47:18 +0200 |
|---|---|---|
| committer | Jean Delvare <khali@endymion.delvare> | 2012-03-26 21:47:18 +0200 |
| commit | b3240e68c05deef2df28db9fc0eea4c277f76494 (patch) | |
| tree | fabf238a44c7d49c4a4c16d83cb8e14181c9dd31 /drivers/i2c | |
| parent | c54c35572a30da2fa028c1dc045facac4ee5640a (diff) | |
| download | lwn-b3240e68c05deef2df28db9fc0eea4c277f76494.tar.gz lwn-b3240e68c05deef2df28db9fc0eea4c277f76494.zip | |
i2c-isch: Decrease delay in command completion check loop
Generally it is not needed to wait for 1 msec, the SMBus get often ready
in less than 200 usecs.
msleep(1) can wait up to 20 msecs... It has a significant impact when
there is a burst of transactions on the bus.
Signed-off-by: Olivier Sobrie <olivier@sobrie.be>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Diffstat (limited to 'drivers/i2c')
| -rw-r--r-- | drivers/i2c/busses/i2c-isch.c | 10 |
1 files changed, 5 insertions, 5 deletions
diff --git a/drivers/i2c/busses/i2c-isch.c b/drivers/i2c/busses/i2c-isch.c index 6561d275b8cf..f90a6057508d 100644 --- a/drivers/i2c/busses/i2c-isch.c +++ b/drivers/i2c/busses/i2c-isch.c @@ -47,7 +47,7 @@ #define SMBBLKDAT (0x20 + sch_smba) /* Other settings */ -#define MAX_TIMEOUT 500 +#define MAX_RETRIES 5000 /* I2C constants */ #define SCH_QUICK 0x00 @@ -68,7 +68,7 @@ static int sch_transaction(void) { int temp; int result = 0; - int timeout = 0; + int retries = 0; dev_dbg(&sch_adapter.dev, "Transaction (pre): CNT=%02x, CMD=%02x, " "ADD=%02x, DAT0=%02x, DAT1=%02x\n", inb(SMBHSTCNT), @@ -100,12 +100,12 @@ static int sch_transaction(void) outb(inb(SMBHSTCNT) | 0x10, SMBHSTCNT); do { - msleep(1); + usleep_range(100, 200); temp = inb(SMBHSTSTS) & 0x0f; - } while ((temp & 0x08) && (timeout++ < MAX_TIMEOUT)); + } while ((temp & 0x08) && (retries++ < MAX_RETRIES)); /* If the SMBus is still busy, we give up */ - if (timeout > MAX_TIMEOUT) { + if (retries > MAX_RETRIES) { dev_err(&sch_adapter.dev, "SMBus Timeout!\n"); result = -ETIMEDOUT; } |