On Fri, Mar 07, 2025 at 12:15:34AM +0200, Jarkko Sakkinen wrote:
On Wed, Mar 05, 2025 at 10:04:25AM +0100, Stefano Garzarella wrote:
On Tue, Mar 04, 2025 at 10:21:55PM +0200, Jarkko Sakkinen wrote:
> On Tue, Mar 04, 2025 at 06:56:02PM +0200, Jarkko Sakkinen wrote:
> > On Mon, 2025-03-03 at 17:21 +0100, Stefano Garzarella wrote:
> > > On Sat, Mar 01, 2025 at 03:45:10AM +0200, Jarkko Sakkinen wrote:
> > > > On Fri, Feb 28, 2025 at 06:07:17PM +0100, Stefano Garzarella wrote:
> > > > > + int (*send_recv)(struct tpm_chip *chip, u8 *buf, size_t
> > > > > buf_len,
> > > > > + size_t to_send);
> > > >
> > > > Please describe the meaning and purpose of to_send.
> > >
> > > Sure, I'll add in the commit description.
> >
> > It's always a command, right? So better be more concerete than
> > "to_send", e.g. "cmd_len".
Right!
> >
> > I'd do instead:
> >
> > if (!chip->send)
> > goto out_recv;
> >
> > And change recv into:
> >
> > int (*recv)(struct tpm_chip *chip, u8 *buf, size_t buf_len,
> > cmd_len);
>
> I think I went here over the top, and *if* we need a new callback
> putting send_recv would be fine. Only thing I'd take from this is to
> rename to_len as cmd_len.
Got it.
>
> However, I don't think there are strong enough reasons to add complexity
> to the callback interface with the basis of this single driver. You
> should deal with this internally inside the driver instead.
>
> So do something along the lines of, e.g.:
>
> 1. Create dummy send() copying the command to internal
> buffer.
> 2. Create ->status() returning zero, and set req_complete_mask and
> req_complete_val to zero.
> 3. Performan transaction in recv().
>
> How you split send_recv() between send() and recv() is up to you. This
> was merely showing that we don't need send_recv() desperately.
We did something similar in v1 [1], but instead of your point 2, we just set
`chip->flags |= TPM_CHIP_FLAG_IRQ;` in the probe() after we allocated the
chip.
Jason suggested the send_recv() ops [2], which I liked, but if you prefer to
avoid that, I can restore what we did in v1 and replace the
TPM_CHIP_FLAG_IRQ hack with your point 2 (or use TPM_CHIP_FLAG_IRQ if you
think it is fine).
@Jarkko, @Jason, I don't have a strong preference about it, so your choice
:-)
I'd say, unless you have actual identified blocker, please go with
a driver where the complexity is managed within the driver.
Yep, got it ;-)
Thanks,
Stefano
