Re: [PATCH v2 1/2] platform: make platform_get_irq_optional() optional
From: Geert Uytterhoeven
Date: Mon Feb 14 2022 - 03:54:31 EST
Hi Sergey,
On Sat, Feb 12, 2022 at 9:17 PM Sergey Shtylyov <s.shtylyov@xxxxxx> wrote:
> This patch is based on the former Andy Shevchenko's patch:
>
> https://lore.kernel.org/lkml/20210331144526.19439-1-andriy.shevchenko@xxxxxxxxxxxxxxx/
>
> Currently platform_get_irq_optional() returns an error code even if IRQ
> resource simply has not been found. It prevents the callers from being
> error code agnostic in their error handling:
>
> ret = platform_get_irq_optional(...);
> if (ret < 0 && ret != -ENXIO)
> return ret; // respect deferred probe
> if (ret > 0)
> ...we get an IRQ...
>
> All other *_optional() APIs seem to return 0 or NULL in case an optional
> resource is not available. Let's follow this good example, so that the
> callers would look like:
>
> ret = platform_get_irq_optional(...);
> if (ret < 0)
> return ret;
> if (ret > 0)
> ...we get an IRQ...
>
> Reported-by: Matthias Schiffer <matthias.schiffer@xxxxxxxxxxxxxxx>
> Signed-off-by: Sergey Shtylyov <s.shtylyov@xxxxxx>
> ---
> Changes in version 2:
Thanks for the update!
> drivers/base/platform.c | 60 +++++++++++++++---------
The core change LGTM.
I'm only looking at Renesas drivers below...
> --- a/drivers/mmc/host/sh_mmcif.c
> +++ b/drivers/mmc/host/sh_mmcif.c
> @@ -1465,14 +1465,14 @@ static int sh_mmcif_probe(struct platform_device *pdev)
> sh_mmcif_sync_reset(host);
> sh_mmcif_writel(host->addr, MMCIF_CE_INT_MASK, MASK_ALL);
>
> - name = irq[1] < 0 ? dev_name(dev) : "sh_mmc:error";
> + name = irq[1] <= 0 ? dev_name(dev) : "sh_mmc:error";
"== 0" should be sufficient here, if the code above would bail out
on errors returned by platform_get_irq_optional(), which it currently
doesn't do.
As this adds missing error handling, this is to be fixed by a separate
patch later?
> ret = devm_request_threaded_irq(dev, irq[0], sh_mmcif_intr,
> sh_mmcif_irqt, 0, name, host);
> if (ret) {
> dev_err(dev, "request_irq error (%s)\n", name);
> goto err_clk;
> }
> - if (irq[1] >= 0) {
> + if (irq[1] > 0) {
OK.
> ret = devm_request_threaded_irq(dev, irq[1],
> sh_mmcif_intr, sh_mmcif_irqt,
> 0, "sh_mmc:int", host);
> --- a/drivers/phy/renesas/phy-rcar-gen3-usb2.c
> +++ b/drivers/phy/renesas/phy-rcar-gen3-usb2.c
> @@ -439,7 +439,7 @@ static int rcar_gen3_phy_usb2_init(struct phy *p)
> u32 val;
> int ret;
>
> - if (!rcar_gen3_is_any_rphy_initialized(channel) && channel->irq >= 0) {
> + if (!rcar_gen3_is_any_rphy_initialized(channel) && channel->irq > 0) {
> INIT_WORK(&channel->work, rcar_gen3_phy_usb2_work);
> ret = request_irq(channel->irq, rcar_gen3_phy_usb2_irq,
> IRQF_SHARED, dev_name(channel->dev), channel);
> @@ -486,7 +486,7 @@ static int rcar_gen3_phy_usb2_exit(struct phy *p)
> val &= ~USB2_INT_ENABLE_UCOM_INTEN;
> writel(val, usb2_base + USB2_INT_ENABLE);
>
> - if (channel->irq >= 0 && !rcar_gen3_is_any_rphy_initialized(channel))
> + if (channel->irq > 0 && !rcar_gen3_is_any_rphy_initialized(channel))
> free_irq(channel->irq, channel);
>
> return 0;
LGTM, but note that all errors returned by platform_get_irq_optional()
are currently ignored, even real errors, which should be propagated
up.
As this adds missing error handling, this is to be fixed by a separate
patch later?
> --- a/drivers/thermal/rcar_gen3_thermal.c
> +++ b/drivers/thermal/rcar_gen3_thermal.c
> @@ -432,6 +432,8 @@ static int rcar_gen3_thermal_request_irqs(struct rcar_gen3_thermal_priv *priv,
> irq = platform_get_irq_optional(pdev, i);
> if (irq < 0)
> return irq;
> + if (!irq)
> + return -ENXIO;
While correct, and preserving existing behavior, this looks strange
to me. Probably this should return zero instead (i.e. the check
above should be changed to "<= 0"), and the caller should start caring
about and propagating up real errors.
As this adds missing error handling, this is to be fixed by a separate
patch later?
>
> irqname = devm_kasprintf(dev, GFP_KERNEL, "%s:ch%d",
> dev_name(dev), i);
> diff --git a/drivers/tty/serial/8250/8250_mtk.c b/drivers/tty/serial/8250/8250_mtk.c
> index fb65dc601b23..328ab074fd89 100644
> --- a/drivers/tty/serial/sh-sci.c
> +++ b/drivers/tty/serial/sh-sci.c
I think you missed
#define SCIx_IRQ_IS_MUXED(port) \
((port)->irqs[SCIx_ERI_IRQ] == \
(port)->irqs[SCIx_RXI_IRQ]) || \
((port)->irqs[SCIx_ERI_IRQ] && \
((port)->irqs[SCIx_RXI_IRQ] < 0))
above? The last condition should become "<= 0".
> @@ -1915,7 +1915,7 @@ static int sci_request_irq(struct sci_port *port)
> * Certain port types won't support all of the
> * available interrupt sources.
> */
> - if (unlikely(irq < 0))
> + if (unlikely(irq <= 0))
> continue;
> }
>
> @@ -1963,7 +1963,7 @@ static void sci_free_irq(struct sci_port *port)
> * Certain port types won't support all of the available
> * interrupt sources.
> */
> - if (unlikely(irq < 0))
> + if (unlikely(irq <= 0))
> continue;
>
> /* Check if already freed (irq was muxed) */
> @@ -2875,7 +2875,7 @@ static int sci_init_single(struct platform_device *dev,
> if (sci_port->irqs[0] < 0)
> return -ENXIO;
>
> - if (sci_port->irqs[1] < 0)
> + if (sci_port->irqs[1] <= 0)
> for (i = 1; i < ARRAY_SIZE(sci_port->irqs); i++)
> sci_port->irqs[i] = sci_port->irqs[0];
>
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx
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