On Mon, Aug 27, 2018 at 9:49 PM Vikash Garodia <vgarodia@xxxxxxxxxxxxxx> wrote:
>
> On 2018-08-27 08:36, Alexandre Courbot wrote:
> > 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?
>
> re-attach is not needed. We can have alloc/attach in init and
> detach/free in deinit.
> map/reset and unmap/reset can continue to remain in boot and shutdown
> calls. Let me
> know if this is good, i can repatch the series.
Yeah, the idea is to avoid repeating operations that do not need to be. Thanks!
