On 10/21/2024 3:01 PM, Konrad Dybcio wrote: > On 21.10.2024 11:25 AM, Akhil P Oommen wrote: >> On Sat, Oct 19, 2024 at 04:14:13PM +0300, Dmitry Baryshkov wrote: >>> On Sat, Oct 19, 2024 at 03:01:46PM +0530, Akhil P Oommen wrote: >>>> On Fri, Oct 18, 2024 at 03:11:38PM +0000, Arnd Bergmann wrote: >>>>> From: Arnd Bergmann <arnd@xxxxxxxx> >>>>> >>>>> Clang-19 and above sometimes end up with multiple copies of the large >>>>> a6xx_hfi_msg_bw_table structure on the stack. The problem is that >>>>> a6xx_hfi_send_bw_table() calls a number of device specific functions to >>>>> fill the structure, but these create another copy of the structure on >>>>> the stack which gets copied to the first. >>>>> >>>>> If the functions get inlined, that busts the warning limit: >>>>> >>>>> drivers/gpu/drm/msm/adreno/a6xx_hfi.c:631:12: error: stack frame size (1032) exceeds limit (1024) in 'a6xx_hfi_send_bw_table' [-Werror,-Wframe-larger-than] >>>> >>>> Why does this warning says that the limit is 1024? 1024 bytes is too small, isn't it? >>> >>> Kernel stacks are expected to be space limited, so 1024 is a logical >>> limit for a single function. >> >> Thanks for the clarification. I think it is better to move this table to >> struct a6xx_gmu which is required anyway when we implement dynamic generation >> of bw table. Also, we can skip initializing it in subsequent gpu wake ups. >> >> Arnd, do you think that would be sufficient? I can send that patch if you >> want help. > > FWIW I implemented this at one point.. ended up only rebasing it for months > as I kept delaying GMU voting until we get an in-tree dram frequency LUT > retrieving driver.. > > https://github.com/SoMainline/linux/commits/konrad/longbois-next/drivers/gpu/drm/msm/adreno > > worth noting that this used to be my R&D branch so this is very much err.. > "provided as-is".. but it did work on 8250! > Thanks, Konrad. "IB vote via GMU" support is there in my bucket list. I can help out if you want to clean this up and send out. -Akhil > Konrad
