Patchwork [v2] i2c-pxa: prepare clock before use

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Submitter Daniel Drake
Date June 17, 2013, 3:30 p.m.
Message ID <20130617153036.67CC84375@dev.laptop.org>
Download mbox | patch
Permalink /patch/251905/
State Accepted
Headers show

Comments

Daniel Drake - June 17, 2013, 3:30 p.m.
On OLPC XO-1.75 (MMP2), a WARN_ON() was occurring during boot
since the clock being enabled by i2c-pxa had not been prepared.

Use clk_prepare_enable() to ensure that the prepare operation
has taken place, and use clk_disable_unprepare() in the matching
shutdown paths.

Signed-off-by: Daniel Drake <dsd@laptop.org>
---
 drivers/i2c/busses/i2c-pxa.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

v2: add the "other half" - thanks Wolfram!
Wolfram Sang - June 18, 2013, 4:12 p.m.
On Mon, Jun 17, 2013 at 11:30:36AM -0400, Daniel Drake wrote:
> On OLPC XO-1.75 (MMP2), a WARN_ON() was occurring during boot
> since the clock being enabled by i2c-pxa had not been prepared.
> 
> Use clk_prepare_enable() to ensure that the prepare operation
> has taken place, and use clk_disable_unprepare() in the matching
> shutdown paths.
> 
> Signed-off-by: Daniel Drake <dsd@laptop.org>

Applied to for-next, thanks!

Patch

diff --git a/drivers/i2c/busses/i2c-pxa.c b/drivers/i2c/busses/i2c-pxa.c
index ea6d45d..fbafed2 100644
--- a/drivers/i2c/busses/i2c-pxa.c
+++ b/drivers/i2c/busses/i2c-pxa.c
@@ -1160,7 +1160,7 @@  static int i2c_pxa_probe(struct platform_device *dev)
 		i2c->adap.class = plat->class;
 	}
 
-	clk_enable(i2c->clk);
+	clk_prepare_enable(i2c->clk);
 
 	if (i2c->use_pio) {
 		i2c->adap.algo = &i2c_pxa_pio_algorithm;
@@ -1202,7 +1202,7 @@  eadapt:
 	if (!i2c->use_pio)
 		free_irq(irq, i2c);
 ereqirq:
-	clk_disable(i2c->clk);
+	clk_disable_unprepare(i2c->clk);
 	iounmap(i2c->reg_base);
 eremap:
 	clk_put(i2c->clk);
@@ -1221,7 +1221,7 @@  static int i2c_pxa_remove(struct platform_device *dev)
 	if (!i2c->use_pio)
 		free_irq(i2c->irq, i2c);
 
-	clk_disable(i2c->clk);
+	clk_disable_unprepare(i2c->clk);
 	clk_put(i2c->clk);
 
 	iounmap(i2c->reg_base);