On 4/11/25 11:57 AM, Dmitry Baryshkov wrote: > On Fri, 11 Apr 2025 at 12:49, Konrad Dybcio > <konrad.dyb...@oss.qualcomm.com> wrote: >> >> On 4/9/25 5:49 PM, Konrad Dybcio wrote: >>> On 4/9/25 5:44 PM, Dmitry Baryshkov wrote: >>>> On 09/04/2025 17:47, Konrad Dybcio wrote: >>>>> SMEM allows the OS to retrieve information about the DDR memory. >>>>> Among that information, is a semi-magic value called 'HBB', or Highest >>>>> Bank address Bit, which multimedia drivers (for hardware like Adreno >>>>> and MDSS) must retrieve in order to program the IP blocks correctly. >>>>> >>>>> This series introduces an API to retrieve that value, uses it in the >>>>> aforementioned programming sequences and exposes available DDR >>>>> frequencies in debugfs (to e.g. pass to aoss_qmp debugfs). More >>>>> information can be exposed in the future, as needed. >>>> >>>> I know that for some platforms HBB differs between GPU and DPU (as it's >>>> being programmed currently). Is there a way to check, which values are we >>>> going to program: >>>> >>>> - SM6115, SM6350, SM6375 (13 vs 14) >> >> SM6350 has INFO_V3 >> SM6375 has INFO_V3_WITH_14_FREQS > > I'm not completely sure what you mean here. I pointed out that these > platforms disagreed upon the HBB value between the DPU/msm_mdss.c and > a6xx_gpu.c. > In some cases (a610/SM6115 and a619/SM6350) that was intentional to > fix screen corruption issues. I don't remember if it was the case for > QCM2290 or not.
As I said below, I couldn't get a good answer yet, as the magic value is not provided explicitly and I'll hopefully be able to derive it from the available data Konrad > >> >>>> - SC8180X (15 vs 16) >> >> So I overlooked the fact that DDR info v3 (e.g. on 8180) doesn't provide >> the HBB value.. Need to add some more sanity checks there. >> >> Maybe I can think up some fallback logic based on the DDR type reported. >> >>>> - QCM2290 (14 vs 15) >> >> I don't have one on hand, could you please give it a go on your RB1? >> I would assume both it and SM6115 also provide v3 though.. >> >> Konrad > > >
