Re: [PATCH v5 16/17] qcom: llcc/edac: Support polling mode for ECC handling

[Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>]

On Sat, Jan 14, 2023 at 02:36:16PM +0100, Borislav Petkov wrote:
> On Wed, Dec 28, 2022 at 02:10:27PM +0530, Manivannan Sadhasivam wrote:
> >  static int qcom_llcc_edac_probe(struct platform_device *pdev)
> >  {
> >  	struct llcc_drv_data *llcc_driv_data = pdev->dev.platform_data;
> > @@ -355,22 +361,31 @@ static int qcom_llcc_edac_probe(struct platform_device *pdev)
> >  	edev_ctl->ctl_name = "llcc";
> >  	edev_ctl->panic_on_ue = LLCC_ERP_PANIC_ON_UE;
> >  
> > +	/* Check if LLCC driver has passed ECC IRQ */
> > +	ecc_irq = llcc_driv_data->ecc_irq;
> > +	if (ecc_irq > 0) {
> > +		/* Use interrupt mode if IRQ is available */
> > +		edac_op_state = EDAC_OPSTATE_INT;
> > +	} else {
> > +		/* Fall back to polling mode otherwise */
> > +		edac_op_state = EDAC_OPSTATE_POLL;
> > +		edev_ctl->poll_msec = ECC_POLL_MSEC;
> > +		edev_ctl->edac_check = llcc_ecc_check;
> > +	}
> > +
> >  	rc = edac_device_add_device(edev_ctl);
> >  	if (rc)
> >  		goto out_mem;
> >  
> >  	platform_set_drvdata(pdev, edev_ctl);
> >  
> > -	/* Request for ecc irq */
> > -	ecc_irq = llcc_driv_data->ecc_irq;
> > -	if (ecc_irq < 0) {
> > -		rc = -ENODEV;
> > -		goto out_dev;
> > -	}
> > -	rc = devm_request_irq(dev, ecc_irq, llcc_ecc_irq_handler,
> > +	/* Request ECC IRQ if available */
> > +	if (ecc_irq > 0) {
> > +		rc = devm_request_irq(dev, ecc_irq, llcc_ecc_irq_handler,
> >  			      IRQF_TRIGGER_HIGH, "llcc_ecc", edev_ctl);
> 
> You need to request the IRQ first and then set edac_op_state above. I.e., this
> devm_request_irq() needs to move in the if (ecc_irq > 0) branch above.

May I know why? I also checked other drivers, most of them are doing the same.

Thanks,
Mani

> 
> -- 
> Regards/Gruss,
>     Boris.
> 
> https://people.kernel.org/tglx/notes-about-netiquette

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