Messages in this thread | | | Date | Fri, 30 Apr 2010 13:07:09 +0300 | From | Sergey Senozhatsky <> | Subject | Re: 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] | |