From: Janusz Użycki <j.uzycki@elproma.com.pl>
Date: Tue, 23 Sep 2014 10:48:26 +0000 (+0200)
Subject: i2c: mxs: detect No Slave Ack on SELECT in PIO mode
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=030f940a535433605e6b4ee43f36189e5cace022;p=GitHub%2Fmoto-9609%2Fandroid_kernel_motorola_exynos9610.git

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>
---

diff --git a/drivers/i2c/busses/i2c-mxs.c b/drivers/i2c/busses/i2c-mxs.c
index 65a21fed08b5..07e1be6f8992 100644
--- a/drivers/i2c/busses/i2c-mxs.c
+++ b/drivers/i2c/busses/i2c-mxs.c
@@ -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);
 
 	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))
 			return -ETIMEDOUT;
 		cond_resched();