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! Konrad
