Re: [PATCH 02/21] tty: serial: qcom_geni_serial: Use OPP API to set clk/perf state

[Rajendra Nayak]

[]..

> > @@ -1318,13 +1321,16 @@ static int qcom_geni_serial_probe(struct platform_device *pdev)
> > ÂÂÂÂÂ if (of_property_read_bool(pdev->dev.of_node, "cts-rts-swap"))
> > ÂÂÂÂÂÂÂÂÂ port->cts_rts_swap = true;
> > +ÂÂÂ port->se.opp = dev_pm_opp_set_clkname(&pdev->dev, "se");
> > +ÂÂÂ dev_pm_opp_of_add_table(&pdev->dev);
> > +
> > ÂÂÂÂÂ uport->private_data = drv;
> > ÂÂÂÂÂ platform_set_drvdata(pdev, port);
> > ÂÂÂÂÂ port->handle_rx = console ? handle_rx_console : handle_rx_uart;
> > ÂÂÂÂÂ ret = uart_add_one_port(drv, uport);
> > ÂÂÂÂÂ if (ret)
> > -ÂÂÂÂÂÂÂ return ret;
> > +ÂÂÂÂÂÂÂ goto err;
> > ÂÂÂÂÂ irq_set_status_flags(uport->irq, IRQ_NOAUTOEN);
> > ÂÂÂÂÂ ret = devm_request_irq(uport->dev, uport->irq, qcom_geni_serial_isr,
> > @@ -1332,7 +1338,7 @@ static int qcom_geni_serial_probe(struct platform_device *pdev)
> > ÂÂÂÂÂ if (ret) {
> > ÂÂÂÂÂÂÂÂÂ dev_err(uport->dev, "Failed to get IRQ ret %d\n", ret);
> > ÂÂÂÂÂÂÂÂÂ uart_remove_one_port(drv, uport);
> > -ÂÂÂÂÂÂÂ return ret;
> > +ÂÂÂÂÂÂÂ goto err;
> > ÂÂÂÂÂ }
> > ÂÂÂÂÂ /*
> > @@ -1349,11 +1355,14 @@ static int qcom_geni_serial_probe(struct platform_device *pdev)
> > ÂÂÂÂÂÂÂÂÂ if (ret) {
> > ÂÂÂÂÂÂÂÂÂÂÂÂÂ device_init_wakeup(&pdev->dev, false);
> > ÂÂÂÂÂÂÂÂÂÂÂÂÂ uart_remove_one_port(drv, uport);
> > -ÂÂÂÂÂÂÂÂÂÂÂ return ret;
> > +ÂÂÂÂÂÂÂÂÂÂÂ goto err;
> > ÂÂÂÂÂÂÂÂÂ }
> > ÂÂÂÂÂ }
> > ÂÂÂÂÂ return 0;
> > +err:
> > +ÂÂÂ dev_pm_opp_of_remove_table(&pdev->dev);
> do we need to call "dev_pm_opp_put_clkname" here and in remove to release clk resource grabbed by
>
> dev_pm_opp_set_clkname(&pdev->dev, "se");?

Thanks for catching this, I did indeed try to call dev_pm_opp_put_clkname() but the way clk_put
is handled in it seems buggy. I need to go back and fix it. Besides I realized dev_pm_opp_of_remove_table()
does go ahead and do a clk_put on the clock.

Viresh, whats the right way to clean up

> > +    port->se.opp = dev_pm_opp_set_clkname(&pdev->dev, "se");
> > +    dev_pm_opp_of_add_table(&pdev->dev);

is it
1. dev_pm_opp_of_remove_table()
   dev_pm_opp_put_clkname()

or
2. dev_pm_opp_put_clkname()
   dev_pm_opp_of_remove_table()

or, what this patch is currently doing, which is just calling dev_pm_opp_of_remove_table()?

Note that both 1. and 2. today result in a crash, since they don't handle clk_put very well.
I can send in a fix if you think dev_pm_opp_put_clkname is needed and in a certain order.

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