On 4/11/25 12:50 PM, Dmitry Baryshkov wrote: > On Fri, Apr 11, 2025 at 12:03:03PM +0200, Konrad Dybcio wrote: >> 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 > > I see... > Is this data even supposed to be poked into? The foo_WITH_bar types > doesn't sound like a very stable API.
Yeah, it was designed with both the producer and consumer being part of a single codebase, always having the data structures in sync.. Konrad
