Re: [PATCH v4 5/5] drm/msm/a6xx: Protect the 0x1c800-0x1e7ff GMU range on A620 and A650

[Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>]

On 10/27/26 8:14 AM, Ishu Brar via B4 Relay wrote:
> From: Ishu Brar <patches@brar.si>
> 
> No protect entry covers the range from 0x1c800 to 0x1e7ff: the entry
> at 0x1a800 ends at 0x1c7ff and the next one starts at 0x1f400. The range
> holds GMU registers, among them GMU_NMI_CONTROL_STATUS (0x1cbf0),
> GMU_BOOT_SLUMBER_OPTION (0x1cbf8), the GX and MX vote indexes (0x1cbf9,
> 0x1cbfa), the DCVS option, setting and return registers (0x1cbfc to
> 0x1cbff) and GMU_CORE_FW_VERSION (0x1d3f8), see a6xx_gmu.xml.
> 
> Add the range as no read/write to the A650 protect list, which A620 and
> A650 share, so that these registers are reserved as well. This follows
> Konrad Dybcio's suggestion; the downstream kgsl protect table of the
> OnePlus Nord (a620_protected_regs) has no entry for this range, so there
> is no downstream reference for it.
> 
> The list is also used by A621, A623, A702 and A704, which I could not
> test. Tested on A620 only (OnePlus Nord, a 7.3 based tree): a Vulkan
> workload ran across GPU frequency changes without protect, fault or GMU
> errors. A write into the range being rejected was not tested.
> 
> Suggested-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>
> Signed-off-by: Ishu Brar <patches@brar.si>
> ---

Reviewed-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>

Konrad