Hi Geert, > -----Original Message----- > From: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx> > Sent: Monday, August 26, 2024 10:56 AM > Subject: Re: [PATCH v3] media: platform: rzg2l-cru: rzg2l-video: Move request_irq() to probe() > > Hi Biju, > > On Mon, Aug 26, 2024 at 11:50 AM Biju Das <biju.das.jz@xxxxxxxxxxxxxx> wrote: > > > From: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx> > > > On Mon, Aug 26, 2024 at 08:08:33AM +0000, Biju Das wrote: > > > > On Monday, August 26, 2024 8:27 AM, claudiu beznea wrote: > > > > > On 24.08.2024 21:21, Biju Das wrote: > > > > > > @@ -270,9 +270,14 @@ static int rzg2l_cru_probe(struct platform_device *pdev) > > > > > > cru->dev = &pdev->dev; > > > > > > cru->info = of_device_get_match_data(&pdev->dev); > > > > > > > > > > > > - cru->image_conv_irq = platform_get_irq(pdev, 0); > > > > > > - if (cru->image_conv_irq < 0) > > > > > > - return cru->image_conv_irq; > > > > > > + irq = platform_get_irq(pdev, 0); > > > > > > + if (irq < 0) > > > > > > + return irq; > > > > > > + > > > > > > + ret = devm_request_irq(&pdev->dev, irq, rzg2l_cru_irq, IRQF_SHARED, > > > > > > + KBUILD_MODNAME, cru); > > > > > > > > > > Because this is requested w/ IRQF_SHARED the free_irq() -> > > > > > __free_irq() [1] will call the IRQ handler to simulate an IRQ > > > > > SHARE scenario where other device generate an interrupt. > > > > > > Good point, I had missed that. > > > > > > > Currently CSI driver is not registered any interrupts and CRU is the single user. > > > > > > Regardless, the fact that the IRQ is requested with IRQF_SHARED > > > means that the IRQ handler needs to be prepared to be called at any > > > time from the point of registration to the point the IRQ is freed. This is tested by > CONFIG_DEBUG_SHIRQ=y, which you should enable for testing. > > > > For single user, testing CONFIG_DEBUG_SHIRQ=y this does not make any > > sense. See [1] [1] > > https://elixir.bootlin.com/linux/v6.11-rc5/source/kernel/irq/manage.c# > > L1965 > > > > > > > > If you don't need to share the interrupt with any other device, you can drop the IRQF_SHARED. > > > > I will drop IRQF_SHARED flags instead as there is single user and will > > send RFC for dropping calling IRQ handler for single user with > > CONFIG_DEBUG_SHIRQ=y > > > > Please let me know is it fine for you? > > IMHO the latter is not a good idea: if you register an interrupt handler with IRQF_SHARED, you should > be prepared for the handler being called at any time, and test that. Regardless of whether there is > only a single user or not. OK, will drop sending RFC. Cheers, Biju
