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i2c: omap: fix draining irq handling 

Commit 0bdfe0cb80 (i2c: omap: sanitize
exit path) changed the interrupt handler to exit early and complete
the transfer after the draining IRQ is handled. As a result, the ARDY
may not be cleared properly, and it may cause all future I2C transfers
to timeout with "timeout waiting for bus ready". This is reproducible
at least with N900 when twl4030_gpio makes a long write (> FIFO size)
during the probe (http://marc.info/?l=linux-omap&m=135818882610432&w=2).

The fix is to continue until we get ARDY interrupt that completes the
transfer. Tested with 3.8-rc4 + N900: 20 boots in a row without errors;
without the patch the problem triggers after few reboots.

Signed-off-by: Aaro Koskinen <aaro.koskinen@iki.fi>
Acked-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
This commit is contained in:
Aaro Koskinen 2013-01-20 20:37:02 +02:00 committed by Wolfram Sang
parent 2c5de558cd
commit 9eb13cf3ec
1 changed files with 2 additions and 2 deletions
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4
drivers/i2c/busses/i2c-omap.c
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@ -963,7 +963,7 @@ omap_i2c_isr_thread(int this_irq, void *dev_id)
i2c_omap_errata_i207(dev, stat);
omap_i2c_ack_stat(dev, OMAP_I2C_STAT_RDR);
break;
continue;
}
if (stat & OMAP_I2C_STAT_RRDY) {
@ -989,7 +989,7 @@ omap_i2c_isr_thread(int this_irq, void *dev_id)
break;
omap_i2c_ack_stat(dev, OMAP_I2C_STAT_XDR);
break;
continue;
}
if (stat & OMAP_I2C_STAT_XRDY) {