On Wed, Oct 08, 2025 at 12:13:03PM +0200, Konrad Dybcio wrote: > On 10/8/25 9:32 AM, Mukesh Ojha wrote: > > On Tue, Oct 07, 2025 at 02:55:04PM -0700, Manivannan Sadhasivam wrote: > >> On Tue, Oct 07, 2025 at 10:18:57PM +0530, Mukesh Ojha wrote: > >>> All the Lemans IOT variants boards are using Gunyah hypervisor which > >>> means that, so far, Linux-based OS could only boot in EL1 on those > >>> devices. However, it is possible for us to boot Linux at EL2 on these > >>> devices [1]. > >>> > >>> When running under Gunyah, remote processor firmware IOMMU streams is > >>> controlled by the Gunyah however when Linux take ownership of it in EL2, > >>> It need to configure it properly to use remote processor. > >>> > >>> Add a EL2-specific DT overlay and apply it to Lemans IOT variant > >>> devices to create -el2.dtb for each of them alongside "normal" dtb. > >>> > >>> [1] > >>> https://docs.qualcomm.com/bundle/publicresource/topics/80-70020-4/boot-developer-touchpoints.html#uefi > >>> > >>> Signed-off-by: Mukesh Ojha <[email protected]> > >>> --- > > [...] > > >>> +&iris { > >>> + /* TODO: Add video-firmware iommus to start IRIS from EL2 */ > >> > >> So the missing 'iommus' property is the only blocker to enable IRIS? > > > > Yes, but this would require some changes in the driver as well to create > > a platform device for the firmware and IOMMU domain, and to attach the > > firmware device to the domain. > > "yes, but actually no" > > > > > There was some discussion around this in v2[1], where I added support > > for video. However, the change involved hooking into the video-firmware > > property, which was used for Venus. There were concerns[2] about following > > the same approach for Iris, and due to that, we have dropped video > > support for now. However, an RFC has been posted from our side to > > handle such scenarios[3], as of now unclear about the direction for > > Iris. > > > > > > [1] https://lore.kernel.org/lkml/[email protected]/ > > > > [2] > > https://lore.kernel.org/lkml/[email protected]/ > > > > [3] > > https://lore.kernel.org/all/[email protected]/ > > > > [4] > > https://lore.kernel.org/lkml/[email protected]/ > > Reword the comment to "/* More driver work is needed */" since there > is nothing more you can do at the moment and you most likely don't > want to block your series on resolving the above entanglement
Sure. > > Konrad -- -Mukesh Ojha
