Messages in this thread | | | Date | Mon, 20 Dec 2021 14:53:27 +0300 | Subject | Re: [PATCH 2/3] i2c: sh_mobile: Use platform_get_irq_optional() to get the interrupt | From | Sergei Shtylyov <> |
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On 20.12.2021 13:17, Geert Uytterhoeven wrote:
[...] >> platform_get_resource(pdev, IORESOURCE_IRQ, ..) relies on static >> allocation of IRQ resources in DT core code, this causes an issue >> when using hierarchical interrupt domains using "interrupts" property >> in the node as this bypasses the hierarchical setup and messes up the >> irq chaining. > > Thanks for your patch! > >> In preparation for removal of static setup of IRQ resource from DT core >> code use platform_get_irq_optional() for DT users only. > > Why only for DT users? > Plenty of driver code shared by Renesas ARM (DT-based) on SuperH > (non-DT) SoCs already uses platform_get_irq_optional(), so I expect > that to work for both. > >> Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com> > >> --- a/drivers/i2c/busses/i2c-sh_mobile.c >> +++ b/drivers/i2c/busses/i2c-sh_mobile.c >> @@ -830,20 +830,41 @@ static void sh_mobile_i2c_release_dma(struct sh_mobile_i2c_data *pd) >> >> static int sh_mobile_i2c_hook_irqs(struct platform_device *dev, struct sh_mobile_i2c_data *pd) >> { >> - struct resource *res; >> - resource_size_t n; >> + struct device_node *np = dev_of_node(&dev->dev); >> int k = 0, ret; >> >> - while ((res = platform_get_resource(dev, IORESOURCE_IRQ, k))) { >> - for (n = res->start; n <= res->end; n++) { >> - ret = devm_request_irq(&dev->dev, n, sh_mobile_i2c_isr, >> - 0, dev_name(&dev->dev), pd); >> + if (!np) { >> + struct resource *res; >> + resource_size_t n; >> + >> + while ((res = platform_get_resource(dev, IORESOURCE_IRQ, k))) { >> + for (n = res->start; n <= res->end; n++) { >> + ret = devm_request_irq(&dev->dev, n, sh_mobile_i2c_isr, >> + 0, dev_name(&dev->dev), pd); >> + if (ret) { >> + dev_err(&dev->dev, "cannot request IRQ %pa\n", &n); >> + return ret; >> + } >> + } >> + k++; >> + } >> + } else { >> + int irq; >> + >> + do { >> + irq = platform_get_irq_optional(dev, k); > > Check for irq == -ENXIO first, to simplify the checks below? > >> + if (irq <= 0 && irq != -ENXIO) >> + return irq ? irq : -ENXIO; > > Can irq == 0 really happen?
Doesn't matter much in this case -- devm_request_irq() happily takes IRQ0. :-)
> All SuperH users of the "i2c-sh_mobile" platform device use an > evt2irq() value that is non-zero. > > I might have missed something, but it seems the only user of IRQ 0 on > SuperH is smsc911x Ethernet in arch/sh/boards/board-apsh4a3a.c and > arch/sh/boards/board-apsh4ad0a.c, which use evt2irq(0x200). > These should have been seeing the "0 is an invalid IRQ number" > warning splat since it was introduced in commit a85a6c86c25be2d2 > ("driver core: platform: Clarify that IRQ 0 is invalid"). Or not:
Warning or no warning, 0 is still returned. :-/ My attempt to put an end to this has stuck waiting a review from the IRQ people...
> the rare users may not have upgraded their kernels beyond v5.8 yet... > >> + if (irq == -ENXIO) >> + break; >> + ret = devm_request_irq(&dev->dev, irq, sh_mobile_i2c_isr, >> + 0, dev_name(&dev->dev), pd); >> if (ret) { >> - dev_err(&dev->dev, "cannot request IRQ %pa\n", &n); >> + dev_err(&dev->dev, "cannot request IRQ %d\n", irq); >> return ret; >> } >> - } >> - k++; >> + k++; >> + } while (irq); >> } >> >> return k > 0 ? 0 : -ENOENT; > > Gr{oetje,eeting}s, > > Geert > > -- > Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org > > In personal conversations with technical people, I call myself a hacker. But > when I'm talking to journalists I just say "programmer" or something like that. > -- Linus Torvalds
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