[07/12] i2c: pxa: Reset i2c controller on timeout in interrupt and pio mode

Message ID 1432818224-17070-8-git-send-email-vaibhav.hiremath@linaro.org
State New
Headers show

Commit Message

Vaibhav Hiremath May 28, 2015, 1:03 p.m.
In case of timeout during msg xfer assert reset to
i2c controller for both interrupt and PIO mode of operation.

Signed-off-by: Jett.Zhou <jtzhou@marvell.com>
[vaibhav.hiremath@linaro.org: Split & merge patches into logical changes
and update the Changelog]
Signed-off-by: Vaibhav Hiremath <vaibhav.hiremath@linaro.org>

Signed-off-by: Vaibhav Hiremath <vaibhav.hiremath@linaro.org>
---
 drivers/i2c/busses/i2c-pxa.c | 8 ++++++++
 1 file changed, 8 insertions(+)

Comments

Vaibhav Hiremath May 29, 2015, 9:19 p.m. | #1
On Saturday 30 May 2015 02:43 AM, Robert Jarzmik wrote:
> Vaibhav Hiremath <vaibhav.hiremath@linaro.org> writes:
>
>> In case of timeout during msg xfer assert reset to
>> i2c controller for both interrupt and PIO mode of operation.
>>
>> Signed-off-by: Jett.Zhou <jtzhou@marvell.com>
>> [vaibhav.hiremath@linaro.org: Split & merge patches into logical changes
>> and update the Changelog]
>> Signed-off-by: Vaibhav Hiremath <vaibhav.hiremath@linaro.org>
>>
>> Signed-off-by: Vaibhav Hiremath <vaibhav.hiremath@linaro.org>
> I have the same comment as before.
> I don't like a reset in the transfer path, especially in normal busy phases for
> slow I2C devices. A quirk as before.
>

Note that this assertion of reset in in case of timeout error.

Timeout error may be due to various reasons, and this is recovery
mechanism.

Thanks,
Vaibhav
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Patch

diff --git a/drivers/i2c/busses/i2c-pxa.c b/drivers/i2c/busses/i2c-pxa.c
index 2777d5c..3c6ebb5 100644
--- a/drivers/i2c/busses/i2c-pxa.c
+++ b/drivers/i2c/busses/i2c-pxa.c
@@ -197,6 +197,8 @@  struct pxa_i2c {
  */
 #define I2C_PXA_SLAVE_ADDR      0x1
 
+static void i2c_pxa_reset(struct pxa_i2c *i2c);
+
 #ifdef DEBUG
 
 struct bits {
@@ -846,6 +848,9 @@  out:
 		ret = I2C_RETRY;
 	}
 
+	if (ret < 0)
+		i2c_pxa_reset(i2c);
+
 	return ret;
 }
 
@@ -912,6 +917,9 @@  static int i2c_pxa_do_xfer(struct pxa_i2c *i2c, struct i2c_msg *msg, int num)
 	}
 
  out:
+	if (ret < 0)
+		i2c_pxa_reset(i2c);
+
 	return ret;
 }