[PATCH v2 1/2] platform: make platform_get_irq_optional() optional
Sergey Shtylyov
s.shtylyov at omp.ru
Mon Feb 14 02:43:11 PST 2022
Hello!
On 2/14/22 11:54 AM, Geert Uytterhoeven wrote:
[...]
>> This patch is based on the former Andy Shevchenko's patch:
>>
>> https://lore.kernel.org/lkml/20210331144526.19439-1-andriy.shevchenko@linux.intel.com/
>>
>> 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 at ew.tq-group.com>
>> Signed-off-by: Sergey Shtylyov <s.shtylyov at omp.ru>
>> ---
>> Changes in version 2:
>
> Thanks for the update!
>
>> drivers/base/platform.c | 60 +++++++++++++++---------
>
> The core change LGTM.
Thanx! :-)
> 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?
Yes.
[...]
>> 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?
Yes.
>> --- 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.
>>
>> 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".
Yes, probably... TY!
> Gr{oetje,eeting}s,
>
> Geert
MBR, Sergey
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