From 030f940a535433605e6b4ee43f36189e5cace022 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Janusz=20U=C5=BCycki?= <j.uzycki@elproma.com.pl>
Date: Tue, 23 Sep 2014 12:48:26 +0200
Subject: [PATCH] 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>
---
drivers/i2c/busses/i2c-mxs.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/drivers/i2c/busses/i2c-mxs.c b/drivers/i2c/busses/i2c-mxs.c
index 65a21fed08b522..07e1be6f8992ef 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();
--
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