Messages in this thread | | | Subject | Re: [RFC v2 03/11] tty: serial: qcom_geni_serial: Use OPP API to set clk/perf state | From | Rajendra Nayak <> | Date | Wed, 12 Aug 2020 14:56:17 +0530 |
| |
On 8/12/2020 1:09 PM, Rajendra Nayak wrote: > > On 8/12/2020 1:05 PM, Amit Pundir wrote: >> Hi Rajendra, >> >> On Wed, 12 Aug 2020 at 11:18, Rajendra Nayak <rnayak@codeaurora.org> wrote: >>> >>> >>> On 8/12/2020 7:03 AM, John Stultz wrote: >>>> On Tue, Aug 11, 2020 at 4:11 PM John Stultz <john.stultz@linaro.org> wrote: >>>>> >>>>> On Wed, Mar 20, 2019 at 2:49 AM Rajendra Nayak <rnayak@codeaurora.org> wrote: >>>>>> >>>>>> geni serial needs to express a perforamnce state requirement on CX >>>>>> depending on the frequency of the clock rates. Use OPP table from >>>>>> DT to register with OPP framework and use dev_pm_opp_set_rate() to >>>>>> set the clk/perf state. >>>>>> >>>>>> Signed-off-by: Rajendra Nayak <rnayak@codeaurora.org> >>>>>> Signed-off-by: Stephen Boyd <swboyd@chromium.org> >>>>>> --- >>>>>> drivers/tty/serial/qcom_geni_serial.c | 15 +++++++++++++-- >>>>>> 1 file changed, 13 insertions(+), 2 deletions(-) >>>>>> >>>>> >>>>> Hey, >>>>> I just wanted to follow up on this patch, as I've bisected it >>>>> (a5819b548af0) down as having broken qca bluetooth on the Dragonboard >>>>> 845c. >>>>> >>>>> I haven't yet had time to debug it yet, but wanted to raise the issue >>>>> in case anyone else has seen similar trouble. >>>> >>>> So I dug in a bit further, and this chunk seems to be causing the issue: >>>>> @@ -961,7 +963,7 @@ static void qcom_geni_serial_set_termios(struct uart_port *uport, >>>>> goto out_restart_rx; >>>>> >>>>> uport->uartclk = clk_rate; >>>>> - clk_set_rate(port->se.clk, clk_rate); >>>>> + dev_pm_opp_set_rate(port->dev, clk_rate); >>>>> ser_clk_cfg = SER_CLK_EN; >>>>> ser_clk_cfg |= clk_div << CLK_DIV_SHFT; >>>>> >>>> >>>> >>>> With that applied, I see the following errors in dmesg and bluetooth >>>> fails to function: >>>> [ 4.763467] qcom_geni_serial 898000.serial: dev_pm_opp_set_rate: >>>> failed to find OPP for freq 102400000 (-34) >>>> [ 4.773493] qcom_geni_serial 898000.serial: dev_pm_opp_set_rate: >>>> failed to find OPP for freq 102400000 (-34) >>>> >>>> With just that chunk reverted on linus/HEAD, bluetooth seems to work ok. >>> >>> This seems like the same issue that was also reported on venus [1] because the >>> clock frequency tables apparently don;t exactly match the achievable clock >>> frequencies (which we also used to construct the OPP tables) >>> >>> Can you try updating the OPP table for QUP to have 102400000 instead of the >>> current 100000000 and see if that fixes it? >> >> That worked. Thanks. >> >> Should this change be common to base sdm845.dtsi or platform specific dts? >> For what it's worth, we see this BT breakage on PocoF1 phone too. > > Thanks for confirming, it will have to be part of the SoC dtsi, and I am > guessing a similar change is perhaps also needed on sc7180. > I will send a patch out to fix the OPP tables for both.
I spent some more time looking at this and it does not look like this is the rounding issues with clock FMAX tables. I had these tables picked from downstream clock code and it turns out these tables were reworked at clock init based on the silicon rev, so I need to fix up the OPP tables accordingly which will add a new OPP entry for 102.4Mhz. I'll post a patch shortly.
> >> >> Regards, >> Amit Pundir >> >> >>> >>> [1] https://lkml.org/lkml/2020/7/27/507 >>> >>>> >>>> thanks >>>> -john >>>> >>> >>> -- >>> QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member >>> of Code Aurora Forum, hosted by The Linux Foundation >
-- QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation
| |