Re: [RFC v2 03/11] tty: serial: qcom_geni_serial: Use OPP API to set clk/perf state
From: John Stultz <hidden>
Date: 2020-08-12 01:33:53
Also in:
dri-devel, linux-arm-msm, linux-pm, linux-scsi, linux-spi, lkml
On Tue, Aug 11, 2020 at 4:11 PM John Stultz [off-list ref] wrote:
On Wed, Mar 20, 2019 at 2:49 AM Rajendra Nayak [off-list ref] wrote:quoted
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 <redacted> Signed-off-by: Stephen Boyd <redacted> --- 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:
quoted hunk ↗ jump to hunk
@@ -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. thanks -john