lkml.org 
[lkml]   [2010]   [Apr]   [30]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: i2c-i801 retries on lost arbitration (resent: no gpg)
On (04/30/10 11:48), Jean Delvare wrote:
> Hi Sergey,
>
>
> > Both i2c spec and ICH7 datasheet requires to restart transaction in
> > case of lost arbitration.
> >
> > "No information is lost during the arbitration process. A master that
> > loses the arbitration can generate clock pulses until the end of the
> > byte in which it loses the arbitration and must restart its transaction
> > when the bus is idle."
> >
> > Please see the following patch. Is it correct?
>
> No, it's not. As you wrote above, this is not specific to the Intel ICH
> but a general I2C issue. As such it must be handled in i2c-core and not
> by individual drivers. And as a matter of fact, it is already handled.
> Look at functions i2c_transfer and i2c_smbus_xfer in i2c-core.c, see
> the comments "Retry automatically on arbitration loss", the code is
> already there. It's just a matter of bus drivers properly setting
> adapter->retries (which i2c-i801.c does already.)
>
Thanks.

> So I don't know which kernel you're using, but with the latest upstream
> kernel, things should work just fine already.
>

OK. Thanks a lot.


Sergey


[unhandled content-type:application/pgp-signature]
\
 
 \ /
  Last update: 2010-04-30 21:15    [W:0.030 / U:0.080 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site