On Fri, Aug 24, 2018 at 9:26 PM Vikash Garodia <vgarodia@xxxxxxxxxxxxxx> wrote:
>
> Hi Alex,
>
> On 2018-08-24 13:09, Alexandre Courbot wrote:
> > On Thu, Aug 23, 2018 at 11:29 PM Vikash Garodia
> > <vgarodia@xxxxxxxxxxxxxx> wrote:
>
> [snip]
>
> >> +struct video_firmware {
> >> + struct device *dev;
> >> + struct iommu_domain *iommu_domain;
> >> +};
> >> +
> >> /**
> >> * struct venus_core - holds core parameters valid for all instances
> >> *
> >> @@ -98,6 +103,7 @@ struct venus_caps {
> >> * @dev: convenience struct device pointer
> >> * @dev_dec: convenience struct device pointer for decoder device
> >> * @dev_enc: convenience struct device pointer for encoder device
> >> + * @fw: a struct for venus firmware info
> >> * @no_tz: a flag that suggests presence of trustzone
> >> * @lock: a lock for this strucure
> >> * @instances: a list_head of all instances
> >> @@ -130,6 +136,7 @@ struct venus_core {
> >> struct device *dev;
> >> struct device *dev_dec;
> >> struct device *dev_enc;
> >> + struct video_firmware fw;
> >
> > Since struct video_firmware is only used here I think you can declare
> > it inline, i.e.
> >
> > struct {
> > struct device *dev;
> > struct iommu_domain *iommu_domain;
> > } fw;
> >
> > This structure is actually a good candidate to hold the firmware
> > memory area start address and size.
>
> I can make it inline.
> Memory area and size are common parameters populated
> locally while loading the firmware with or without tz. Firmware struct
> has
> info more specific to firmware device.
>
> [snip]
>
> >
> >> +{
> >> + struct iommu_domain *iommu_dom;
> >> + struct device *dev;
> >> + int ret;
> >> +
> >> + dev = core->fw.dev;
> >> + if (!dev)
> >> + return -EPROBE_DEFER;
> >> +
> >> + iommu_dom = iommu_domain_alloc(&platform_bus_type);
> >> + if (!iommu_dom) {
> >> + dev_err(dev, "Failed to allocate iommu domain\n");
> >> + return -ENOMEM;
> >> + }
> >> +
> >> + ret = iommu_attach_device(iommu_dom, dev);
> >> + if (ret) {
> >> + dev_err(dev, "could not attach device\n");
> >> + goto err_attach;
> >> + }
> >
> > I think like the above belongs more in venus_firmware_init()
> > (introduced in patch 4/4) than here. There is no reason to
> > detach/reattach the iommu if we stop the firmware.
>
> Consider the case when we want to reload the firmware during error
> recovery.
> Boot and shutdown will be needed in such case without the need to
> populate
> the firmware device again.
Is there a need to reattach the iommu domain in case of an error?
