Patchwork [2/2] i2c: designware: make i2c xfers non-interruptible

login
register
mail settings
Submitter Christian Ruppert
Date June 6, 2013, 1:43 p.m.
Message ID <1370526216-10060-2-git-send-email-christian.ruppert@abilis.com>
Download mbox | patch
Permalink /patch/249424/
State Superseded
Headers show

Comments

Christian Ruppert - June 6, 2013, 1:43 p.m.
When the process at the source of an i2c transfer is killed in the
middle of the transfer, the transfer is interrupted. Interrupted
transfers might cause buggy slaves on the bus (or higher level drivers)
to go haywire.
This patch forces ongoing i2c transfers to finish properly, even if the
initiating process is killed.

Signed-off-by: Christian Ruppert <christian.ruppert@abilis.com>
---
 drivers/i2c/busses/i2c-designware-core.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
Mika Westerberg - June 7, 2013, 5:25 a.m.
On Thu, Jun 06, 2013 at 03:43:36PM +0200, Christian Ruppert wrote:
> When the process at the source of an i2c transfer is killed in the
> middle of the transfer, the transfer is interrupted. Interrupted
> transfers might cause buggy slaves on the bus (or higher level drivers)
> to go haywire.
> This patch forces ongoing i2c transfers to finish properly, even if the
> initiating process is killed.

I already sent a similar patch ;-)

https://patchwork.kernel.org/patch/2601241/

However, it is not yet picked by Wolfram.
--
To unsubscribe from this list: send the line "unsubscribe linux-i2c" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Christian Ruppert - June 7, 2013, 7:55 a.m.
On Fri, Jun 07, 2013 at 08:25:55AM +0300, Mika Westerberg wrote:
> On Thu, Jun 06, 2013 at 03:43:36PM +0200, Christian Ruppert wrote:
> > When the process at the source of an i2c transfer is killed in the
> > middle of the transfer, the transfer is interrupted. Interrupted
> > transfers might cause buggy slaves on the bus (or higher level drivers)
> > to go haywire.
> > This patch forces ongoing i2c transfers to finish properly, even if the
> > initiating process is killed.
> 
> I already sent a similar patch ;-)
> 
> https://patchwork.kernel.org/patch/2601241/
> 
> However, it is not yet picked by Wolfram.

Oops, this looks like a human race condition :) I checked main line and
Wolfram's git but didn't think of checking patchwork. I'll rebase the
second patch on yours.

Patch

diff --git a/drivers/i2c/busses/i2c-designware-core.c b/drivers/i2c/busses/i2c-designware-core.c
index 65c0c7a..d903368 100644
--- a/drivers/i2c/busses/i2c-designware-core.c
+++ b/drivers/i2c/busses/i2c-designware-core.c
@@ -585,7 +585,7 @@  i2c_dw_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
 	i2c_dw_xfer_init(dev);
 
 	/* wait for tx to complete */
-	ret = wait_for_completion_interruptible_timeout(&dev->cmd_complete, HZ);
+	ret = wait_for_completion_timeout(&dev->cmd_complete, HZ);
 	if (ret == 0) {
 		dev_err(dev->dev, "controller timed out\n");
 		/* i2c_dw_init implicitly disables the adapter */