On 1.06.2023 16:14, Jeffrey Hugo wrote:
> On Wed, May 31, 2023 at 3:01 AM Konrad Dybcio <konrad.dybcio@xxxxxxxxxx> wrote:
>>
>> The SMMU GDSC doesn't have to be ALWAYS-ON and shouldn't feature the
>> HW_CTRL flag (it's separate from hw_ctrl_addr). In addition to that,
>> it should feature a cxc entry for bimc_smmu_axi_clk and be marked as
>> votable.
>>
>> Fix all of these issues.
>>
>> Fixes: d14b15b5931c ("clk: qcom: Add MSM8998 Multimedia Clock Controller (MMCC) driver")
>> Signed-off-by: Konrad Dybcio <konrad.dybcio@xxxxxxxxxx>
>
> Was this tested on a system where the bootloader has enabled the
> display and it is active during Linux boot?
No, I only have a device whose bootloader doesn't initialize display.
>
> I seem to recall that in that scenario, Linux would boot up, see that
> the GDSC is on, not see any clients for it (still initializing), turn
> it off, and kill the display which then results in either a mess of
> errors or a bus lockup.
I see 2 possible scenarios: either the display shuts off (because
somebody hasn't described the hardware properly and Linux isn't)
aware of all dependencies, or we get bus errors because we only
shut down / initialize some hardware partially, also possibly due
to bad dependency description.
Konrad
>
> -Jeff
