From mboxrd@z Thu Jan  1 00:00:00 1970
From: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Subject: Re: [PATCH] net/smsc911x: Fix deferred probe for interrupt
Date: Mon, 31 Aug 2015 20:05:02 +0300
Message-ID: <55E4893E.2010309@cogentembedded.com>
References: <1440787815-24655-1-git-send-email-tony@atomide.com>
 <55E22540.3060307@cogentembedded.com> <55E45E9E.1090900@ti.com>
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Cc: netdev@vger.kernel.org, linux-omap@vger.kernel.org,
	Steve Glendinning <steve.glendinning@shawell.net>
To: Grygorii Strashko <grygorii.strashko@ti.com>,
	Tony Lindgren <tony@atomide.com>,
	David Miller <davem@davemloft.net>,
	Geert Uytterhoeven <geert+renesas@glider.be>
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Hello.

On 08/31/2015 05:03 PM, Grygorii Strashko wrote:

>>> The interrupt handler may not be available when smsc911x probes if the
>>> interrupt handler is a GPIO controller for example. Let's fix that
>>> by adding handling for -EPROBE_DEFER.
>>
>>> Cc: Steve Glendinning <steve.glendinning@shawell.net>
>>> Signed-off-by: Tony Lindgren <tony@atomide.com>
>>> ---
>>>    drivers/net/ethernet/smsc/smsc911x.c | 5 ++++-
>>>    1 file changed, 4 insertions(+), 1 deletion(-)
>>>
>>> diff --git a/drivers/net/ethernet/smsc/smsc911x.c
>>> b/drivers/net/ethernet/smsc/smsc911x.c
>>> index 959aeea..cb9f166f 100644
>>> --- a/drivers/net/ethernet/smsc/smsc911x.c
>>> +++ b/drivers/net/ethernet/smsc/smsc911x.c
>>> @@ -2435,7 +2435,10 @@ static int smsc911x_drv_probe(struct
>>> platform_device *pdev)
>>>        res_size = resource_size(res);
>>>
>>>        irq = platform_get_irq(pdev, 0);
>>> -    if (irq <= 0) {
>>> +    if (irq == -EPROBE_DEFER) {
>>> +        retval = -EPROBE_DEFER;
>>> +        goto out_0;
>>> +    } else if (irq <= 0) {
>>>            pr_warn("Could not allocate irq resource\n");
>>>            retval = -ENODEV;
>>
>>      I'd propagate the error code from platfrom_get_irq() instead (in
>> fact, I've submitted a couple of such patches yesterday and they have
>> been already merged).

> Have you paid some attention on current platform_get_irq_() implementation?

> The platform_get_irq() can return 0 in case of DT-boot.

    This is what's indeed worth filtering out and converting to -ENODEV. ;-)
But my patches just ignored this possibility. I'm not at all fond of Linus' 
idea about IRQ0 being invalid, BTW...

WBR, Sergei