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 13:09:44 +0530 |
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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.
> > 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
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