i2c: mxs: detect No Slave Ack on SELECT in PIO mode

i2cdetect scanned i2c bus slow because the i2c-mxs driver ignored the
NO_SLAVE_ACK bit during busy-waiting loop. Thanks to the patch, the
speedup happens.

Signed-off-by: Janusz Uzycki <j.uzycki@elproma.com.pl>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
This commit is contained in:
Janusz Użycki 2014-09-23 12:48:26 +02:00 committed by Wolfram Sang
parent d8e0a86f97
commit 030f940a53

View File

@ -307,6 +307,9 @@ static int mxs_i2c_pio_wait_xfer_end(struct mxs_i2c_dev *i2c)
unsigned long timeout = jiffies + msecs_to_jiffies(1000); unsigned long timeout = jiffies + msecs_to_jiffies(1000);
while (readl(i2c->regs + MXS_I2C_CTRL0) & MXS_I2C_CTRL0_RUN) { while (readl(i2c->regs + MXS_I2C_CTRL0) & MXS_I2C_CTRL0_RUN) {
if (readl(i2c->regs + MXS_I2C_CTRL1) &
MXS_I2C_CTRL1_NO_SLAVE_ACK_IRQ)
return -ENXIO;
if (time_after(jiffies, timeout)) if (time_after(jiffies, timeout))
return -ETIMEDOUT; return -ETIMEDOUT;
cond_resched(); cond_resched();