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Message-ID: <j5zai7pw7pxe2owjsoq2ncwhsmwe2llmcvb7vp46xi757eamub@inefovgffgpp>
Date: Fri, 29 Mar 2024 22:54:36 +0100
From: Andi Shyti <andi.shyti@...nel.org>
To: Mukesh Kumar Savaliya <quic_msavaliy@...cinc.com>
Cc: konrad.dybcio@...aro.org, andersson@...nel.org,
linux-arm-msm@...r.kernel.org, linux-kernel@...r.kernel.org, linux-i2c@...r.kernel.org,
quic_vdadhani@...cinc.com, Vinod Koul <vkoul@...nel.org>
Subject: Re: [PATCH v1] i2c: i2c-qcom-geni: Serve transfer during early
resume stage
Hi Mukesh,
On Thu, Mar 28, 2024 at 06:07:43PM +0530, Mukesh Kumar Savaliya wrote:
> pm_runtime_get_sync() function fails during PM early resume and returning
> -EACCES because runtime PM for the device is disabled at the early stage
> causing i2c transfer to fail. Make changes to serve transfer with force
> resume.
>
> 1. Register interrupt with IRQF_EARLY_RESUME and IRQF_NO_SUSPEND flags
> to avoid timeout of transfer when IRQ is not enabled during early stage.
> 2. Do force resume if pm_runtime_get_sync() is failing after system
> suspend when runtime PM is not enabled.
> 3. Increment power usage count after forced resume to balance
> it against regular runtime suspend.
>
> Co-developed-by: Viken Dadhaniya <quic_vdadhani@...cinc.com>
> Signed-off-by: Viken Dadhaniya <quic_vdadhani@...cinc.com>
> Signed-off-by: Mukesh Kumar Savaliya <quic_msavaliy@...cinc.com>
Is this a fix? O mostly an improvement?
..
> gi2c->err = 0;
> reinit_completion(&gi2c->done);
> - ret = pm_runtime_get_sync(gi2c->se.dev);
> - if (ret < 0) {
> - dev_err(gi2c->se.dev, "error turning SE resources:%d\n", ret);
> - pm_runtime_put_noidle(gi2c->se.dev);
> - /* Set device in suspended since resume failed */
> - pm_runtime_set_suspended(gi2c->se.dev);
> - return ret;
> +
> + if (!pm_runtime_enabled(dev) && gi2c->suspended) {
> + dev_dbg(gi2c->se.dev, "RT_PM disabled, Do force resume, usage_count:%d\n",
dev
nit: you could leave a space after the ':'.
> + atomic_read(&dev->power.usage_count));
> + ret = geni_i2c_force_resume(gi2c);
> + if (ret)
> + return ret;
> + } else {
> + ret = pm_runtime_get_sync(dev);
> + if (ret == -EACCES && gi2c->suspended) {
> + dev_dbg(gi2c->se.dev, "PM get_sync() failed-%d, force resume\n", ret);
dev
> + ret = geni_i2c_force_resume(gi2c);
> + if (ret)
> + return ret;
> + }
Are we missing some cases here? Do we need a few more else's?
Andi
> }
>
> qcom_geni_i2c_conf(gi2c);
> @@ -702,8 +730,15 @@ static int geni_i2c_xfer(struct i2c_adapter *adap,
> else
> ret = geni_i2c_fifo_xfer(gi2c, msgs, num);
>
> - pm_runtime_mark_last_busy(gi2c->se.dev);
> - pm_runtime_put_autosuspend(gi2c->se.dev);
> + if (!pm_runtime_enabled(dev) && !gi2c->suspended) {
> + pm_runtime_put_noidle(dev);
> + pm_runtime_set_suspended(dev);
this looks like repeated code, how about making it a function?
> + gi2c->suspended = 0;
> + } else {
> + pm_runtime_mark_last_busy(gi2c->se.dev);
> + pm_runtime_put_autosuspend(gi2c->se.dev);
> + }
> +
> gi2c->cur = NULL;
> gi2c->err = 0;
> return ret;
> @@ -820,7 +855,7 @@ static int geni_i2c_probe(struct platform_device *pdev)
> init_completion(&gi2c->done);
> spin_lock_init(&gi2c->lock);
> platform_set_drvdata(pdev, gi2c);
> - ret = devm_request_irq(dev, gi2c->irq, geni_i2c_irq, 0,
> + ret = devm_request_irq(dev, gi2c->irq, geni_i2c_irq, IRQF_EARLY_RESUME | IRQF_NO_SUSPEND,
Can you provide a bit more information on how an early interrupt
would be handled once the device is resumed?
Thanks,
Andi
> dev_name(dev), gi2c);
> if (ret) {
> dev_err(dev, "Request_irq failed:%d: err:%d\n",
> --
> 2.25.1
>
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