Re: [PATCH v11] i2c: virtio: add a virtio i2c frontend driver

From: Wolfram Sang
Date: Fri Jul 02 2021 - 03:36:54 EST


On Fri, Jul 02, 2021 at 12:51:27PM +0530, Viresh Kumar wrote:
> On 02-07-21, 15:15, Jie Deng wrote:
> > Then what is the need to design this interface as "return the number of
> > messages successfully
> > processed, or a negative value on error". Just return success or fail is
> > enough.

Let me quote a comment from the I2C core which is there since 2008:

/* REVISIT the fault reporting model here is weak:
*
* - When we get an error after receiving N bytes from a slave,
* there is no way to report "N".
*
* - When we get a NAK after transmitting N bytes to a slave,
* there is no way to report "N" ... or to let the master
* continue executing the rest of this combined message, if
* that's the appropriate response.
*
* - When for example "num" is two and we successfully complete
* the first message but get an error part way through the
* second, it's unclear whether that should be reported as
* one (discarding status on the second message) or errno
* (discarding status on the first one).
*/

> for 5.14-rc1/2.. So it would be better if you resend the next version as soon as
> possible :)

I won't be around for the next two weeks after today.

Attachment: signature.asc
Description: PGP signature