commit: http://blackfin.uclinux.org/git/?p=linux-kernel;a=commitdiff;h=45978af423c5bccb24e68ab20504ebc6cae4d4e8 branch: http://blackfin.uclinux.org/git/?p=linux-kernel;a=shortlog;h=refs/heads/trunk
Some fault i2c device may hold the sda/scl line and cause i2c driver wait in the BUS busy loop. The I2C framework already retry the transfer loop before timeout. Return -EAGAIN instead of pull BUSBUSY in the other loop. Signed-off-by: Sonic Zhang <[email protected]> --- drivers/i2c/busses/i2c-bfin-twi.c | 18 ++++-------------- 1 files changed, 4 insertions(+), 14 deletions(-) diff --git a/drivers/i2c/busses/i2c-bfin-twi.c b/drivers/i2c/busses/i2c-bfin-twi.c index bb9dde7..e1abf50 100644 --- a/drivers/i2c/busses/i2c-bfin-twi.c +++ b/drivers/i2c/busses/i2c-bfin-twi.c @@ -247,8 +247,6 @@ static irqreturn_t bfin_twi_interrupt_entry(int irq, void *dev_id) return IRQ_HANDLED; } -#define BFIN_TWI_BUSY_TIMEOUT 1000 - /* * One i2c master transfer */ @@ -258,16 +256,12 @@ static int bfin_twi_do_master_xfer(struct i2c_adapter *adap, struct bfin_twi_iface *iface = adap->algo_data; struct i2c_msg *pmsg; int rc = 0; - unsigned int busy_timeout = BFIN_TWI_BUSY_TIMEOUT; if (!(read_CONTROL(iface) & TWI_ENA)) return -ENXIO; - while (read_MASTER_STAT(iface) & BUSBUSY) { - if (--busy_timeout == 0) - return -EBUSY; - yield(); - } + if (read_MASTER_STAT(iface) & BUSBUSY) + return -EAGAIN; iface->pmsg = msgs; iface->msg_num = num; @@ -364,16 +358,12 @@ int bfin_twi_do_smbus_xfer(struct i2c_adapter *adap, u16 addr, { struct bfin_twi_iface *iface = adap->algo_data; int rc = 0; - unsigned int busy_timeout = BFIN_TWI_BUSY_TIMEOUT; if (!(read_CONTROL(iface) & TWI_ENA)) return -ENXIO; - while (read_MASTER_STAT(iface) & BUSBUSY) { - if (--busy_timeout == 0) - return -EBUSY; - yield(); - } + if (read_MASTER_STAT(iface) & BUSBUSY) + return -EAGAIN; iface->writeNum = 0; iface->readNum = 0;
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