Re: [PATCH 06/11] media: iris: Fix VM count passed to firmware

[Vishnu Reddy]

On 4/14/2026 8:50 PM, Dmitry Baryshkov wrote:
> On Tue, Apr 14, 2026 at 10:30:02AM +0530, Vishnu Reddy wrote:
> > On Glymur, firmware interprets the value written to CPU_CS_SCIACMDARG3 as
> > the number of virtual machines (VMs) and internally adds 1 to it. Writing
> Does this apply to Glymur only or to other platforms too?

Only Glymur firmware is currently reading this register and other 
platform firmwares are
ignoring this.

Thanks,
Vishnu Reddy.

> > 1 causes firmware to treat it as 2 VMs. Since only one VM is required,
> > remove this write to leave the register at its reset value of 0. This does
> > not affect other platforms as only Glymur firmware uses this register,
> > earlier platform firmwares ignore it.
> >
> > Fixes: abf5bac63f68a ("media: iris: implement the boot sequence of the firmware")
> > Cc:stable@xxxxxxxxxxxxxxx
> > Signed-off-by: Vishnu Reddy<busanna.reddy@xxxxxxxxxxxxxxxx>
> > ---
> >   drivers/media/platform/qcom/iris/iris_vpu_common.c | 1 -
> >   1 file changed, 1 deletion(-)
> >
> > diff --git a/drivers/media/platform/qcom/iris/iris_vpu_common.c b/drivers/media/platform/qcom/iris/iris_vpu_common.c
> > index 548e5f1727fd..bfd1e762c38e 100644
> > --- a/drivers/media/platform/qcom/iris/iris_vpu_common.c
> > +++ b/drivers/media/platform/qcom/iris/iris_vpu_common.c
> > @@ -78,7 +78,6 @@ int iris_vpu_boot_firmware(struct iris_core *core)
> >   	iris_vpu_setup_ucregion_memory_map(core);
> >   
> >   	writel(ctrl_init, core->reg_base + CTRL_INIT);
> > -	writel(0x1, core->reg_base + CPU_CS_SCIACMDARG3);
> >   
> >   	while (!ctrl_status && count < max_tries) {
> >   		ctrl_status = readl(core->reg_base + CTRL_STATUS);
> >
> > --
> > 2.34.1