Messages in this thread | | | Date | Thu, 1 Jul 2021 11:48:46 +0530 | From | Viresh Kumar <> | Subject | Re: [PATCH v11] i2c: virtio: add a virtio i2c frontend driver |
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On 01-07-21, 14:10, Jie Deng wrote: > I think a fixed number of sgs will make things easier to develop backend.
Yeah, but it looks awkward to send a message buffer which isn't used at all. From protocol's point of view, it just looks wrong/buggy.
The backend can just look at the number of elements received, they can either be 2 (in case of zero-length) transfer, or 3 (for read/write) and any other number is invalid.
> If you prefer to parse the number of descriptors instead of using the msg > length to > > distinguish the zero-length request from other requests, I'm OK to set a > limit.
My concern is more about the specification here first.
> if (!msgs[i].len) { > sg_init_one(&msg_buf, reqs[i].buf, msgs[i].len); > > if (msgs[i].flags & I2C_M_RD) > sgs[outcnt + incnt++] = &msg_buf; > else > sgs[outcnt++] = &msg_buf; > }
> > > +#ifdef CONFIG_PM_SLEEP > > You could avoid this pair of ifdef by creating dummy versions of below > > routines for !CONFIG_PM_SLEEP case. Up to you. > > > Thank you. I'd like to keep the same.
Sure.
-- viresh
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