[PATCH 6/9] drm/panthor: Reset GPU after L2 cache power off

[Marek Vasut]

On 3/3/25 1:35 PM, Boris Brezillon wrote:

Hi,

>> This looks like it has been part of a R50 release of the DDK, which is recent
>> enough to consider it up-to-date. The issues you're seeing with fast resume are
>> probably due to some integration issues or other quirks.
>>
>> Boris has the most recent experience with playing with fast resume, maybe
>> he can share some tips on where to add messages in Panthor to try to debug
>> your problem.
> 
> If you end up with fast_reset=true, that means the FW claims it entered
> a suspend state from which is can resume quickly (fast-reset), and in
> that case, we're only supposed to power on the L2 block at resume time
> AFAIK. If there's a component that can tell us more, it's probably the
> FW, unfortunately, it doesn't tell us much through the FW interface,
> especially if it's not booting properly. Do you hit this error [1]
> without this patch, and if you do, what's the status reported there?
> 
> [1]https://elixir.bootlin.com/linux/v6.14-rc4/source/drivers/gpu/drm/panthor/panthor_fw.c#L1051

Sorry for the late reply. I get the following, so I think the status is 
"fatal" ?

panthor 4d900000.gpu: [drm] clock rate = 1000000000
panthor 4d900000.gpu: EM: created perf domain
panthor 4d900000.gpu: [drm] mali-g310 id 0xac74 major 0x0 minor 0x0 
status 0x1
panthor 4d900000.gpu: [drm] Features: L2:0x7110306 Tiler:0x809 Mem:0x1 
MMU:0x2830 AS:0xff
panthor 4d900000.gpu: [drm] shader_present=0x1 l2_present=0x1 
tiler_present=0x1
panthor 4d900000.gpu: [drm] Firmware protected mode entry not be 
supported, ignoring
panthor 4d900000.gpu: [drm] Firmware git sha: 
8e5cfcfec20cc8aff8509d37e72babc935d34a3b
panthor 4d900000.gpu: [drm] CSF FW using interface v1.1.0, Features 0x0 
Instrumentation features 0x71
[drm] Initialized panthor 1.3.0 for 4d900000.gpu on minor 0
panthor 4d900000.gpu: [drm] *ERROR* Failed to boot MCU (status=fatal)
panthor 4d900000.gpu: [drm] *ERROR* FW fast reset failed
panthor 4d900000.gpu: [drm] *ERROR* Fast reset failed, trying a slow reset
panthor 4d900000.gpu: [drm] *ERROR* Failed to boot MCU (status=fatal)
panthor 4d900000.gpu: [drm] *ERROR* FW slow reset failed