[PATCH] USB: host: ehci: Add error handling in ehci_mxc_drv_probe()

[PATCH] USB: host: ehci: Add error handling in ehci_mxc_drv_probe()

[Tang Bin]

The function ehci_mxc_drv_probe() does not perform sufficient error
checking after executing platform_get_irq(), thus fix it.

Fixes: 7e8d5cd93fa ("USB: Add EHCI support for MX27 and MX31 based boards")
Signed-off-by: Zhang Shengju <zhangshengju@cmss.chinamobile.com>
Signed-off-by: Tang Bin <tangbin@cmss.chinamobile.com>
---
 drivers/usb/host/ehci-mxc.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/usb/host/ehci-mxc.c b/drivers/usb/host/ehci-mxc.c
index a1eb5ee77..a0b42ba59 100644
--- a/drivers/usb/host/ehci-mxc.c
+++ b/drivers/usb/host/ehci-mxc.c
@@ -50,6 +50,8 @@ static int ehci_mxc_drv_probe(struct platform_device *pdev)
 	}
 
 	irq = platform_get_irq(pdev, 0);
+	if (irq < 0)
+		return irq;
 
 	hcd = usb_create_hcd(&ehci_mxc_hc_driver, dev, dev_name(dev));
 	if (!hcd)
-- 
2.20.1.windows.1

Re: [PATCH] USB: host: ehci: Add error handling in ehci_mxc_drv_probe()

[Greg KH]

On Fri, May 08, 2020 at 07:44:53PM +0800, Tang Bin wrote:
> The function ehci_mxc_drv_probe() does not perform sufficient error
> checking after executing platform_get_irq(), thus fix it.
> 
> Fixes: 7e8d5cd93fa ("USB: Add EHCI support for MX27 and MX31 based boards")
> Signed-off-by: Zhang Shengju <zhangshengju@cmss.chinamobile.com>
> Signed-off-by: Tang Bin <tangbin@cmss.chinamobile.com>
> ---
>  drivers/usb/host/ehci-mxc.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/drivers/usb/host/ehci-mxc.c b/drivers/usb/host/ehci-mxc.c
> index a1eb5ee77..a0b42ba59 100644
> --- a/drivers/usb/host/ehci-mxc.c
> +++ b/drivers/usb/host/ehci-mxc.c
> @@ -50,6 +50,8 @@ static int ehci_mxc_drv_probe(struct platform_device *pdev)
>  	}
>  
>  	irq = platform_get_irq(pdev, 0);
> +	if (irq < 0)
> +		return irq;

<= ?

Re: [PATCH] USB: host: ehci: Add error handling in ehci_mxc_drv_probe()

[Alan Stern]

On Fri, 8 May 2020, Tang Bin wrote:

> The function ehci_mxc_drv_probe() does not perform sufficient error
> checking after executing platform_get_irq(), thus fix it.

Aside from the "irq <= 0" issue, the Subject: line should say 
"ehci-mxc", not "ehci".

Alan Stern

> Fixes: 7e8d5cd93fa ("USB: Add EHCI support for MX27 and MX31 based boards")
> Signed-off-by: Zhang Shengju <zhangshengju@cmss.chinamobile.com>
> Signed-off-by: Tang Bin <tangbin@cmss.chinamobile.com>
> ---
>  drivers/usb/host/ehci-mxc.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/drivers/usb/host/ehci-mxc.c b/drivers/usb/host/ehci-mxc.c
> index a1eb5ee77..a0b42ba59 100644
> --- a/drivers/usb/host/ehci-mxc.c
> +++ b/drivers/usb/host/ehci-mxc.c
> @@ -50,6 +50,8 @@ static int ehci_mxc_drv_probe(struct platform_device *pdev)
>  	}
>  
>  	irq = platform_get_irq(pdev, 0);
> +	if (irq < 0)
> +		return irq;
>  
>  	hcd = usb_create_hcd(&ehci_mxc_hc_driver, dev, dev_name(dev));
>  	if (!hcd)
> 

Re: [PATCH] USB: host: ehci: Add error handling inehci_mxc_drv_probe()

[Tang Bin]

Hi, Greg:

On 2020/5/8 19:48, Greg KH wrote:
> On Fri, May 08, 2020 at 07:44:53PM +0800, Tang Bin wrote:
>> The function ehci_mxc_drv_probe() does not perform sufficient error
>> checking after executing platform_get_irq(), thus fix it.
>>
>> Fixes: 7e8d5cd93fa ("USB: Add EHCI support for MX27 and MX31 based boards")
>> Signed-off-by: Zhang Shengju <zhangshengju@cmss.chinamobile.com>
>> Signed-off-by: Tang Bin <tangbin@cmss.chinamobile.com>
>> ---
>>   drivers/usb/host/ehci-mxc.c | 2 ++
>>   1 file changed, 2 insertions(+)
>>
>> diff --git a/drivers/usb/host/ehci-mxc.c b/drivers/usb/host/ehci-mxc.c
>> index a1eb5ee77..a0b42ba59 100644
>> --- a/drivers/usb/host/ehci-mxc.c
>> +++ b/drivers/usb/host/ehci-mxc.c
>> @@ -50,6 +50,8 @@ static int ehci_mxc_drv_probe(struct platform_device *pdev)
>>   	}
>>   
>>   	irq = platform_get_irq(pdev, 0);
>> +	if (irq < 0)
>> +		return irq;
> <= ?

In the file 'drivers/base/platform.c'， the function platform_get_irq() 
is explained and used as follows:

      * Gets an IRQ for a platform device and prints an error message if 
finding the
      * IRQ fails. Device drivers should check the return value for 
errors so as to
      * not pass a negative integer value to the request_irq() APIs.
      *
      * Example:
      *        int irq = platform_get_irq(pdev, 0);
      *        if (irq < 0)
      *            return irq;
      *
      * Return: IRQ number on success, negative error number on failure.

And in my hardware experiment, even if I set the irq failed deliberately 
in the DTS, the returned value is negative instead of zero.

Thanks for your patience and replay.

Tang Bin

Re: [PATCH] USB: host: ehci: Add error handling inehci_mxc_drv_probe()

[Greg KH]

On Fri, May 08, 2020 at 09:55:53PM +0800, Tang Bin wrote:
> Hi, Greg:
> 
> On 2020/5/8 19:48, Greg KH wrote:
> > On Fri, May 08, 2020 at 07:44:53PM +0800, Tang Bin wrote:
> > > The function ehci_mxc_drv_probe() does not perform sufficient error
> > > checking after executing platform_get_irq(), thus fix it.
> > > 
> > > Fixes: 7e8d5cd93fa ("USB: Add EHCI support for MX27 and MX31 based boards")
> > > Signed-off-by: Zhang Shengju <zhangshengju@cmss.chinamobile.com>
> > > Signed-off-by: Tang Bin <tangbin@cmss.chinamobile.com>
> > > ---
> > >   drivers/usb/host/ehci-mxc.c | 2 ++
> > >   1 file changed, 2 insertions(+)
> > > 
> > > diff --git a/drivers/usb/host/ehci-mxc.c b/drivers/usb/host/ehci-mxc.c
> > > index a1eb5ee77..a0b42ba59 100644
> > > --- a/drivers/usb/host/ehci-mxc.c
> > > +++ b/drivers/usb/host/ehci-mxc.c
> > > @@ -50,6 +50,8 @@ static int ehci_mxc_drv_probe(struct platform_device *pdev)
> > >   	}
> > >   	irq = platform_get_irq(pdev, 0);
> > > +	if (irq < 0)
> > > +		return irq;
> > <= ?
> 
> In the file 'drivers/base/platform.c'， the function platform_get_irq() is
> explained and used as follows:
> 
>      * Gets an IRQ for a platform device and prints an error message if
> finding the
>      * IRQ fails. Device drivers should check the return value for errors so
> as to
>      * not pass a negative integer value to the request_irq() APIs.
>      *
>      * Example:
>      *        int irq = platform_get_irq(pdev, 0);
>      *        if (irq < 0)
>      *            return irq;
>      *
>      * Return: IRQ number on success, negative error number on failure.
> 
> And in my hardware experiment, even if I set the irq failed deliberately in
> the DTS, the returned value is negative instead of zero.

Please read the thread at
	https://lore.kernel.org/r/20200501224042.141366-1-helgaas%40kernel.org
for more details about this.

thanks,

greg k-h

Re: [PATCH] USB: host: ehci: Add error handlinginehci_mxc_drv_probe()

[Tang Bin]

On 2020/5/8 22:31, Greg KH wrote:
> On Fri, May 08, 2020 at 09:55:53PM +0800, Tang Bin wrote:
>> Hi, Greg:
>>
>> On 2020/5/8 19:48, Greg KH wrote:
>>> On Fri, May 08, 2020 at 07:44:53PM +0800, Tang Bin wrote:
>>>> The function ehci_mxc_drv_probe() does not perform sufficient error
>>>> checking after executing platform_get_irq(), thus fix it.
>>>>
>>>> Fixes: 7e8d5cd93fa ("USB: Add EHCI support for MX27 and MX31 based boards")
>>>> Signed-off-by: Zhang Shengju <zhangshengju@cmss.chinamobile.com>
>>>> Signed-off-by: Tang Bin <tangbin@cmss.chinamobile.com>
>>>> ---
>>>>    drivers/usb/host/ehci-mxc.c | 2 ++
>>>>    1 file changed, 2 insertions(+)
>>>>
>>>> diff --git a/drivers/usb/host/ehci-mxc.c b/drivers/usb/host/ehci-mxc.c
>>>> index a1eb5ee77..a0b42ba59 100644
>>>> --- a/drivers/usb/host/ehci-mxc.c
>>>> +++ b/drivers/usb/host/ehci-mxc.c
>>>> @@ -50,6 +50,8 @@ static int ehci_mxc_drv_probe(struct platform_device *pdev)
>>>>    	}
>>>>    	irq = platform_get_irq(pdev, 0);
>>>> +	if (irq < 0)
>>>> +		return irq;
>>> <= ?
>> In the file 'drivers/base/platform.c'， the function platform_get_irq() is
>> explained and used as follows:
>>
>>       * Gets an IRQ for a platform device and prints an error message if
>> finding the
>>       * IRQ fails. Device drivers should check the return value for errors so
>> as to
>>       * not pass a negative integer value to the request_irq() APIs.
>>       *
>>       * Example:
>>       *        int irq = platform_get_irq(pdev, 0);
>>       *        if (irq < 0)
>>       *            return irq;
>>       *
>>       * Return: IRQ number on success, negative error number on failure.
>>
>> And in my hardware experiment, even if I set the irq failed deliberately in
>> the DTS, the returned value is negative instead of zero.
> Please read the thread at
> 	https://lore.kernel.org/r/20200501224042.141366-1-helgaas%40kernel.org
> for more details about this.
>
Great, It looks beautiful, finally someone took a knife to the file 
'platform.c'.

I have been studied this place for a long time, and don't know what 
platform can return 0, which made me curious.

So the example should be:

      *        int irq = platform_get_irq(pdev, 0);
      *        if (irq <= 0)
      *            return irq;

Thanks,

Tang Bin

Re: [PATCH] USB: host: ehci: Add error handlinginehci_mxc_drv_probe()

[Sergei Shtylyov]

On 05/08/2020 06:03 PM, Tang Bin wrote:

>>>> On Fri, May 08, 2020 at 07:44:53PM +0800, Tang Bin wrote:
>>>>> The function ehci_mxc_drv_probe() does not perform sufficient error
>>>>> checking after executing platform_get_irq(), thus fix it.
>>>>>
>>>>> Fixes: 7e8d5cd93fa ("USB: Add EHCI support for MX27 and MX31 based boards")
>>>>> Signed-off-by: Zhang Shengju <zhangshengju@cmss.chinamobile.com>
>>>>> Signed-off-by: Tang Bin <tangbin@cmss.chinamobile.com>
>>>>> ---
>>>>>    drivers/usb/host/ehci-mxc.c | 2 ++
>>>>>    1 file changed, 2 insertions(+)
>>>>>
>>>>> diff --git a/drivers/usb/host/ehci-mxc.c b/drivers/usb/host/ehci-mxc.c
>>>>> index a1eb5ee77..a0b42ba59 100644
>>>>> --- a/drivers/usb/host/ehci-mxc.c
>>>>> +++ b/drivers/usb/host/ehci-mxc.c
>>>>> @@ -50,6 +50,8 @@ static int ehci_mxc_drv_probe(struct platform_device *pdev)
>>>>>        }
>>>>>        irq = platform_get_irq(pdev, 0);
>>>>> +    if (irq < 0)
>>>>> +        return irq;
>>>> <= ?
>>> In the file 'drivers/base/platform.c'， the function platform_get_irq() is
>>> explained and used as follows:
>>>
>>>       * Gets an IRQ for a platform device and prints an error message if
>>> finding the
>>>       * IRQ fails. Device drivers should check the return value for errors so
>>> as to
>>>       * not pass a negative integer value to the request_irq() APIs.
>>>       *
>>>       * Example:
>>>       *        int irq = platform_get_irq(pdev, 0);
>>>       *        if (irq < 0)
>>>       *            return irq;
>>>       *
>>>       * Return: IRQ number on success, negative error number on failure.
>>>
>>> And in my hardware experiment, even if I set the irq failed deliberately in
>>> the DTS, the returned value is negative instead of zero.
>> Please read the thread at
>>     https://lore.kernel.org/r/20200501224042.141366-1-helgaas%40kernel.org
>> for more details about this.
>>
> Great, It looks beautiful, finally someone took a knife to the file 'platform.c'.

   I thought I did that already couple years ago, when returned 0 from platform_get_irq() could mean both IRQ # and error... :-)

> 
> I have been studied this place for a long time, and don't know what platform can return 0, which made me curious.
> 
> So the example should be:
> 
>      *        int irq = platform_get_irq(pdev, 0);
>      *        if (irq <= 0)
>      *            return irq;

   And you then return 0 (success) as if your probe() succeeded. Congratulations! :-P

> 
> Thanks,
> 
> Tang Bin

MBR, Sergei

Re: [PATCH] USB: host: ehci: Add error handling in ehci_mxc_drv_probe()

[Sergei Shtylyov]

On 05/08/2020 02:48 PM, Greg KH wrote:

>> The function ehci_mxc_drv_probe() does not perform sufficient error
>> checking after executing platform_get_irq(), thus fix it.
>>
>> Fixes: 7e8d5cd93fa ("USB: Add EHCI support for MX27 and MX31 based boards")
>> Signed-off-by: Zhang Shengju <zhangshengju@cmss.chinamobile.com>
>> Signed-off-by: Tang Bin <tangbin@cmss.chinamobile.com>
>> ---
>>  drivers/usb/host/ehci-mxc.c | 2 ++
>>  1 file changed, 2 insertions(+)
>>
>> diff --git a/drivers/usb/host/ehci-mxc.c b/drivers/usb/host/ehci-mxc.c
>> index a1eb5ee77..a0b42ba59 100644
>> --- a/drivers/usb/host/ehci-mxc.c
>> +++ b/drivers/usb/host/ehci-mxc.c
>> @@ -50,6 +50,8 @@ static int ehci_mxc_drv_probe(struct platform_device *pdev)
>>  	}
>>  
>>  	irq = platform_get_irq(pdev, 0);
>> +	if (irq < 0)
>> +		return irq;
> 
> <= ?

   I thought I've fixed the ambivalent zero bug some years ago... 
   Please don't do this...

MBR, Sergei

Re: [PATCH] USB: host: ehci: Add error handlinginehci_mxc_drv_probe()

[Tang Bin]

Hi Sergei:

On 2020/5/9 4:27, Sergei Shtylyov wrote:
> On 05/08/2020 06:03 PM, Tang Bin wrote:
>
>>>>> On Fri, May 08, 2020 at 07:44:53PM +0800, Tang Bin wrote:
>>>>>> The function ehci_mxc_drv_probe() does not perform sufficient error
>>>>>> checking after executing platform_get_irq(), thus fix it.
>>>>>>
>>>>>> Fixes: 7e8d5cd93fa ("USB: Add EHCI support for MX27 and MX31 based boards")
>>>>>> Signed-off-by: Zhang Shengju <zhangshengju@cmss.chinamobile.com>
>>>>>> Signed-off-by: Tang Bin <tangbin@cmss.chinamobile.com>
>>>>>> ---
>>>>>>     drivers/usb/host/ehci-mxc.c | 2 ++
>>>>>>     1 file changed, 2 insertions(+)
>>>>>>
>>>>>> diff --git a/drivers/usb/host/ehci-mxc.c b/drivers/usb/host/ehci-mxc.c
>>>>>> index a1eb5ee77..a0b42ba59 100644
>>>>>> --- a/drivers/usb/host/ehci-mxc.c
>>>>>> +++ b/drivers/usb/host/ehci-mxc.c
>>>>>> @@ -50,6 +50,8 @@ static int ehci_mxc_drv_probe(struct platform_device *pdev)
>>>>>>         }
>>>>>>         irq = platform_get_irq(pdev, 0);
>>>>>> +    if (irq < 0)
>>>>>> +        return irq;
>>>>> <= ?
>>>> In the file 'drivers/base/platform.c'， the function platform_get_irq() is
>>>> explained and used as follows:
>>>>
>>>>        * Gets an IRQ for a platform device and prints an error message if
>>>> finding the
>>>>        * IRQ fails. Device drivers should check the return value for errors so
>>>> as to
>>>>        * not pass a negative integer value to the request_irq() APIs.
>>>>        *
>>>>        * Example:
>>>>        *        int irq = platform_get_irq(pdev, 0);
>>>>        *        if (irq < 0)
>>>>        *            return irq;
>>>>        *
>>>>        * Return: IRQ number on success, negative error number on failure.
>>>>
>>>> And in my hardware experiment, even if I set the irq failed deliberately in
>>>> the DTS, the returned value is negative instead of zero.
>>> Please read the thread at
>>>      https://lore.kernel.org/r/20200501224042.141366-1-helgaas%40kernel.org
>>> for more details about this.
>>>
>> Great, It looks beautiful, finally someone took a knife to the file 'platform.c'.
>     I thought I did that already couple years ago, when returned 0 from platform_get_irq() could mean both IRQ # and error... :-)
Can you tell me what platform can returned 0? I want to do this test in 
the hardware.
>> I have been studied this place for a long time, and don't know what platform can return 0, which made me curious.
>>
>> So the example should be:
>>
>>       *        int irq = platform_get_irq(pdev, 0);
>>       *        if (irq <= 0)
>>       *            return irq;
>     And you then return 0 (success) as if your probe() succeeded. Congratulations! :-P

Thanks,

Tang Bin

Re: [PATCH] USB: host: ehci: Add error handling in ehci_mxc_drv_probe()

[Tang Bin]

Hi gregkh:

On 2020/5/8 21:51, Alan Stern wrote:
> On Fri, 8 May 2020, Tang Bin wrote:
>
>> The function ehci_mxc_drv_probe() does not perform sufficient error
>> checking after executing platform_get_irq(), thus fix it.
> Aside from the "irq <= 0" issue, the Subject: line should say
> "ehci-mxc", not "ehci".
>
I know this patch need v2, whether just fix the subject?

Thanks,

Tang Bin

>
>> Fixes: 7e8d5cd93fa ("USB: Add EHCI support for MX27 and MX31 based boards")
>> Signed-off-by: Zhang Shengju <zhangshengju@cmss.chinamobile.com>
>> Signed-off-by: Tang Bin <tangbin@cmss.chinamobile.com>
>> ---
>>   drivers/usb/host/ehci-mxc.c | 2 ++
>>   1 file changed, 2 insertions(+)
>>
>> diff --git a/drivers/usb/host/ehci-mxc.c b/drivers/usb/host/ehci-mxc.c
>> index a1eb5ee77..a0b42ba59 100644
>> --- a/drivers/usb/host/ehci-mxc.c
>> +++ b/drivers/usb/host/ehci-mxc.c
>> @@ -50,6 +50,8 @@ static int ehci_mxc_drv_probe(struct platform_device *pdev)
>>   	}
>>   
>>   	irq = platform_get_irq(pdev, 0);
>> +	if (irq < 0)
>> +		return irq;
>>   
>>   	hcd = usb_create_hcd(&ehci_mxc_hc_driver, dev, dev_name(dev));
>>   	if (!hcd)
>>

Re: [PATCH] USB: host: ehci: Add error handling in ehci_mxc_drv_probe()

[Greg KH]

On Wed, May 13, 2020 at 08:55:59PM +0800, Tang Bin wrote:
> Hi gregkh:
> 
> On 2020/5/8 21:51, Alan Stern wrote:
> > On Fri, 8 May 2020, Tang Bin wrote:
> > 
> > > The function ehci_mxc_drv_probe() does not perform sufficient error
> > > checking after executing platform_get_irq(), thus fix it.
> > Aside from the "irq <= 0" issue, the Subject: line should say
> > "ehci-mxc", not "ehci".
> > 
> I know this patch need v2, whether just fix the subject?

0 is an invalid irq.