[PATCH v6 10/11] modesetting: Disable Reverse PRIME for i915

[Alex Goins]

Thanks for the feedback, Emil!

> IMHO the proposed patch does not sound like a reasonable long-term
> solution. Ideally the driver will expose a flag, based on which Xorg
> will enable/disable reverse prime. That said, as a short-term fix this
> is fine, barring the issues mentioned below.

I'll address this lower in the thread.

> > diff --git a/hw/xfree86/drivers/modesetting/driver.c b/hw/xfree86/drivers/modesetting/driver.c
> > index f7abd1e..403cb96 100644
> > --- a/hw/xfree86/drivers/modesetting/driver.c
> > +++ b/hw/xfree86/drivers/modesetting/driver.c
> > @@ -1378,9 +1378,13 @@ ScreenInit(ScreenPtr pScreen, int argc, char **argv)
> >              xf86DrvMsg(pScrn->scrnIndex, X_ERROR,
> >                         "Failed to initialize the Present extension.\n");
> >          }
> > -        /* enable reverse prime if we are a GPU screen, and accelerated */
> > -        if (pScreen->isGPU)
> > -            ms->drmmode.reverse_prime_offload_mode = TRUE;
> > +        /* enable reverse prime if we are a GPU screen, and accelerated, and not
> > +         * i915. i915 is happy scanning out from sysmem. */
> > +        if (pScreen->isGPU) {
> > +            drmVersionPtr version = drmGetVersion(ms->drmmode.fd);
> > +            if (strncmp("i915", version->name, version->name_len))
> 'version' can be null.
> 
> > +                ms->drmmode.reverse_prime_offload_mode = TRUE;
> > +        }
> We're leaking 'version'.
> 
> Same two apply for the UDL patch.
> 
> Regards,
> Emil

You're right, thanks for the catch. I have these fixed locally now, but I'll
wait a little while to see if there's any more feedback before sending out
another revision.

Thanks,
Alex