Hello!

On 2/14/22 11:54 AM, Geert Uytterhoeven wrote:

[...]

quoted

This patch is based on the former Andy Shevchenko's patch:

https://lore.kernel.org/lkml/20210331144526.19439-1-andriy.shevchenko@linux.intel.com/ (local)

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 <redacted>
Signed-off-by: Sergey Shtylyov <redacted>
---
Changes in version 2:

Thanks for the update!

quoted

 drivers/base/platform.c                  | 60 +++++++++++++++---------

The core change LGTM.

   Thanx! :-)

I'm only looking at Renesas drivers below...

quoted

--- 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?

   Yes.

[...]

quoted

                ret = devm_request_threaded_irq(dev, irq[1],
                                                sh_mmcif_intr, sh_mmcif_irqt,
                                                0, "sh_mmc:int", host);

quoted

--- 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?

   Yes.

quoted

--- 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.

   Hm, you're right... should be <= 0 there, it seems.

As this adds missing error handling, this is to be fixed by a separate
patch later?

   Propagating errors from the probe() method is a matter of separate patch, yes.

quoted

                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

quoted

--- 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".

   Yes, probably... TY!

Gr{oetje,eeting}s,

                        Geert

MBR, Sergey