Messages in this thread | | | Date | Mon, 12 Jan 2015 14:25:37 +0100 | From | Marc Kleine-Budde <> | Subject | Re: [PATCH v4] can: Convert to runtime_pm |
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On 01/12/2015 07:59 AM, Appana Durga Kedareswara Rao wrote: > Hi Marc, > >> -----Original Message----- >> From: Marc Kleine-Budde [mailto:mkl@pengutronix.de] >> Sent: Sunday, January 11, 2015 9:11 PM >> To: Appana Durga Kedareswara Rao >> Cc: linux-can@vger.kernel.org; netdev@vger.kernel.org; linux- >> kernel@vger.kernel.org; Soren Brinkmann; grant.likely@linaro.org; >> wg@grandegger.com >> Subject: Re: [PATCH v4] can: Convert to runtime_pm >> >> On 01/11/2015 06:34 AM, Appana Durga Kedareswara Rao wrote: >> [...] >>>>> return ret; >>>>> } >>>>> >>>>> priv->write_reg(priv, XCAN_MSR_OFFSET, 0); >>>>> priv->write_reg(priv, XCAN_SRR_OFFSET, XCAN_SRR_CEN_MASK); >>>>> >>>>> if (netif_running(ndev)) { >>>>> priv->can.state = CAN_STATE_ERROR_ACTIVE; >>>> >>>> What happens if the device was not in ACTIVE state prior to the >>>> runtime_suspend? >>>> >>> >>> I am not sure about the state of CAN at this point of time. >>> I just followed what other drivers are following for run time suspend :). >> >> Please check the state of the hardware if you go with bus off into suspend >> and then resume. >> > > if (netif_running(ndev)) { > if (isr & XCAN_IXR_BSOFF_MASK) { > priv->can.state = CAN_STATE_BUS_OFF; > priv->write_reg(priv, XCAN_SRR_OFFSET, > XCAN_SRR_RESET_MASK); > } else if ((status & XCAN_SR_ESTAT_MASK) == > XCAN_SR_ESTAT_MASK) { > priv->can.state = CAN_STATE_ERROR_PASSIVE; > } else if (status & XCAN_SR_ERRWRN_MASK) { > priv->can.state = CAN_STATE_ERROR_WARNING; > } else { > priv->can.state = CAN_STATE_ERROR_ACTIVE; > } > } > > Is the above code snippet ok for you?
Yes, but what's the state of the hardware when it wakes up again?
> >>>>> netif_device_attach(ndev); >>>>> netif_start_queue(ndev); >>>>> } >>>>> >>>>> return 0; >>>>> } >>>> >>>> >>>>> >>>>> @@ -1020,9 +1035,9 @@ static int __maybe_unused xcan_resume(struct >>>>> device *dev) >>>>> >>>>> priv->write_reg(priv, XCAN_MSR_OFFSET, 0); >>>>> priv->write_reg(priv, XCAN_SRR_OFFSET, XCAN_SRR_CEN_MASK); >>>>> - priv->can.state = CAN_STATE_ERROR_ACTIVE; >>>>> >>>>> if (netif_running(ndev)) { >>>>> + priv->can.state = CAN_STATE_ERROR_ACTIVE; >>>>> netif_device_attach(ndev); >>>>> netif_start_queue(ndev); >>>>> } >>>>> @@ -1030,7 +1045,10 @@ static int __maybe_unused >> xcan_resume(struct >>>> device *dev) >>>>> return 0; >>>>> } >>>>> >>>>> -static SIMPLE_DEV_PM_OPS(xcan_dev_pm_ops, xcan_suspend, >>>> xcan_resume); >>>>> +static const struct dev_pm_ops xcan_dev_pm_ops = { >>>>> + SET_SYSTEM_SLEEP_PM_OPS(xcan_suspend, xcan_resume) >>>>> + SET_PM_RUNTIME_PM_OPS(xcan_runtime_suspend, >>>> xcan_runtime_resume, >>>>> +NULL) }; >>>>> >>>>> /** >>>>> * xcan_probe - Platform registration call @@ -1071,7 +1089,7 @@ >>>>> static int xcan_probe(struct platform_device *pdev) >>>>> return -ENOMEM; >>>>> >>>>> priv = netdev_priv(ndev); >>>>> - priv->dev = ndev; >>>>> + priv->dev = &pdev->dev; >>>>> priv->can.bittiming_const = &xcan_bittiming_const; >>>>> priv->can.do_set_mode = xcan_do_set_mode; >>>>> priv->can.do_get_berr_counter = xcan_get_berr_counter; @@ - >>>> 1137,15 >>>>> +1155,22 @@ static int xcan_probe(struct platform_device *pdev) >>>>> >>>>> netif_napi_add(ndev, &priv->napi, xcan_rx_poll, rx_max); >>>>> >>>>> + pm_runtime_set_active(&pdev->dev); >>>>> + pm_runtime_irq_safe(&pdev->dev); >>>>> + pm_runtime_enable(&pdev->dev); >>>>> + pm_runtime_get_sync(&pdev->dev); >>>> Check error values? >>> >>> Ok >>>>> + >>>>> ret = register_candev(ndev); >>>>> if (ret) { >>>>> dev_err(&pdev->dev, "fail to register failed >>>>> (err=%d)\n", >>>> ret); >>>>> + pm_runtime_put(priv->dev); >>>> >>>> Please move the pm_runtime_put into the common error exit path. >>>> >>> >>> Ok >>> >>>>> goto err_unprepare_disable_busclk; >>>>> } >>>>> >>>>> devm_can_led_init(ndev); >>>>> - clk_disable_unprepare(priv->bus_clk); >>>>> - clk_disable_unprepare(priv->can_clk); >>>>> + >>>>> + pm_runtime_put(&pdev->dev); >>>>> + >>>>> netdev_dbg(ndev, "reg_base=0x%p irq=%d clock=%d, tx fifo >>>> depth:%d\n", >>>>> priv->reg_base, ndev->irq, priv->can.clock.freq, >>>>> priv->tx_max); >>>>> >>>> >>>> I think you have to convert the _remove() function, too. Have a look >>>> at the gpio-zynq.c driver: >>>> >>>>> static int zynq_gpio_remove(struct platform_device *pdev) { >>>>> struct zynq_gpio *gpio = platform_get_drvdata(pdev); >>>>> >>>>> pm_runtime_get_sync(&pdev->dev); >>>> >>>> However I don't understand why the get_sync() is here. Maybe Sören >>>> can help? >>> >>> I converted the remove function to use the run-time PM and . >>> Below is the remove code snippet. >>> >>> ret = pm_runtime_get_sync(&pdev->dev); >>> if (ret < 0) { >>> netdev_err(ndev, "%s: pm_runtime_get failed(%d)\n", >>> __func__, ret); >>> return ret; >>> } >>> >>> if (set_reset_mode(ndev) < 0) >>> netdev_err(ndev, "mode resetting failed!\n"); >>> >>> unregister_candev(ndev); >>> netif_napi_del(&priv->napi); >>> free_candev(ndev); >> >>> pm_runtime_disable(&pdev->dev); >> >> Can this make a call to xcan_runtime_*()? I'm asking since the ndev has >> been unregistered and already free()ed. Better move this directly after the >> set_reset_mode(). This way you are symmetric to the probe() function. > > If I move the pm_runtime_disable after the set_reset_mode > I am getting the below error. > ERROR: > xilinx_can e0008000.can can0 (unregistering): xcan_get_berr_counter: pm_runtime_get fail > > If I move the pm_runtime_disable after unregister_candev everything is working fine.
Fine - but who calls xcan_get_berr_counter here? Can you add a dump_stack() here?
Marc -- Pengutronix e.K. | Marc Kleine-Budde | Industrial Linux Solutions | Phone: +49-231-2826-924 | Vertretung West/Dortmund | Fax: +49-5121-206917-5555 | Amtsgericht Hildesheim, HRA 2686 | http://www.pengutronix.de |
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