Hi Will,
On Tue, Aug 27, 2024 at 09:18:47AM -0700, Nicolin Chen wrote:
> On Tue, Aug 27, 2024 at 04:57:48PM +0100, Robin Murphy wrote:
> > > > -static void acpi_smmu_get_options(u32 model, struct arm_smmu_device *smmu)
> > > > +static int acpi_smmu_iort_probe_model(struct acpi_iort_node *node,
> > > > + struct arm_smmu_device *smmu)
> > > > {
> > > > - switch (model) {
> > > > + struct acpi_iort_smmu_v3 *iort_smmu =
> > > > + (struct acpi_iort_smmu_v3 *)node->node_data;
> > > > +
> > > > + switch (iort_smmu->model) {
> > > > case ACPI_IORT_SMMU_V3_CAVIUM_CN99XX:
> > > > smmu->options |= ARM_SMMU_OPT_PAGE0_REGS_ONLY;
> > > > break;
> > > > case ACPI_IORT_SMMU_V3_HISILICON_HI161X:
> > > > smmu->options |= ARM_SMMU_OPT_SKIP_PREFETCH;
> > > > break;
> > > > + case ACPI_IORT_SMMU_V3_GENERIC:
> > > > + break;
> > > > + default:
> > > > + dev_err(smmu->dev, "Unknown/unsupported IORT model!\n");
> > > > + return -ENXIO;
> > >
> > > We probably don't want this 'default' case, otherwise the driver will
> > > need to be updated every time there's a new model.
> >
> > ...although the intent is very strongly that there should never be any
> > new models, because by now hardware should really not be failing to
> > implement SMMU_IIDR correctly. In some ways, having this might help
> > further discourage people from abusing the mechanism and making random
> > stuff up in their firmware :/
>
> I don't have a strong feeling about this, though Robin's point was
> my intention here.
>
> Apart from this "default case", I typo-ed the function name in the
> patch subject and commit message. Also, there's a missed kdoc line
> in struct tegra241_cmdqv (PATCH-8).
>
> So, I prepared a v14:
> https://github.com/nicolinc/iommufd/commits/vcmdq_in_kernel-v14
> v14 changelog (attaching git-diff at the EOM):
> * Rebased on Will's for-joerg/arm-smmu/updates
> * Added a missed kdoc for "dev" in struct tegra241_cmdqv
> * Dropped the default case in acpi_smmu_iort_probe_model()
> (did this before seeing Robin's mail here.)
>
> Let's see what makes the best for you, Will.
I just sent v14 by keeping the default case, given Robin's remarks
here. If you'd like to remove the default case, please feel free!
Thank you
Nicolin
