On 14.07.2023 15:02, Johan Hovold wrote:

The operating-performance-point vote needs to be dropped when shutting down the port to avoid wasting power by keeping resources like power domains in an unnecessarily high performance state (e.g. when a UART connected Bluetooth controller is not in use).

Fixes: a5819b548af0 ("tty: serial: qcom_geni_serial: Use OPP API to set clk/perf state") Cc: stable@vger.kernel.org # 5.9 Cc: Rajendra Nayak quic_rjendra@quicinc.com Cc: Matthias Kaehlcke mka@chromium.org Signed-off-by: Johan Hovold johan+linaro@kernel.org

---

I don't know a whole lot about this subsystem, but the PM call has a pointer to uport which already contains this clock rate.. Is it zeroed out by the core before we reach it, which would prevent us from reusing it?

Konrad

drivers/tty/serial/qcom_geni_serial.c | 5 +++++ 1 file changed, 5 insertions(+)

diff --git a/drivers/tty/serial/qcom_geni_serial.c b/drivers/tty/serial/qcom_geni_serial.c index b825b05e6137..8be896dbaa88 100644 --- a/drivers/tty/serial/qcom_geni_serial.c +++ b/drivers/tty/serial/qcom_geni_serial.c @@ -126,6 +126,7 @@ struct qcom_geni_serial_port { dma_addr_t rx_dma_addr; bool setup; unsigned int baud;

• unsigned long clk_rate; void *rx_buf; u32 loopback; bool brk;

@@ -1249,6 +1250,7 @@ static void qcom_geni_serial_set_termios(struct uart_port *uport, baud * sampling_rate, clk_rate, clk_div); uport->uartclk = clk_rate;

• port->clk_rate = clk_rate; dev_pm_opp_set_rate(uport->dev, clk_rate); ser_clk_cfg = SER_CLK_EN; ser_clk_cfg |= clk_div << CLK_DIV_SHFT;

@@ -1513,10 +1515,13 @@ static void qcom_geni_serial_pm(struct uart_port *uport, if (new_state == UART_PM_STATE_ON && old_state == UART_PM_STATE_OFF) { geni_icc_enable(&port->se);

• if (port->clk_rate)
  

• 	dev_pm_opp_set_rate(uport->dev, port->clk_rate);
  

  geni_se_resources_on(&port->se); } else if (new_state == UART_PM_STATE_OFF && old_state == UART_PM_STATE_ON) { geni_se_resources_off(&port->se);

• dev_pm_opp_set_rate(uport->dev, 0);
  

  geni_icc_disable(&port->se); }

}