Re: [RFC PATCH] smsc911x: Ignore error return from device_get_phy_mode()

[Guenter Roeck <linux@roeck-us.net>]

On 08/26/2015 12:44 PM, Jeremy Linton wrote:
> On 08/26/2015 01:49 PM, Guenter Roeck wrote:
>> Check the return value from device_property_read_u32() to see if there
>> is a suitable firmware interface to read the data, and abort if not.
>> The function should return -ENXIO in that case; however, it returns
>> -ENODATA. Check for both.
>>
>> Fixes: 62ee783bf1f8 ("smsc911x: Fix crash seen if neither ACPI nor OF is configured or used")
>> Signed-off-by: Guenter Roeck <linux@roeck-us.net>
>> ---
>> Needs testing. RFC because I am not sure if the -ENODATA check is acceptable.
>
> I'm not really sure about it myself. I can think of cases where it might cause problems. That said it does work in an ACPI environment with or without the _DSD block. If the DSD/property isn't set, obviously the device doesn't configure (but it doesn't crash either) so that is good and an overall improvement for ACPI.
>
> Also, I personally might have hoisted the reg-io-width ahead of the device_get_phy_mode() and removed the phy checks, but I don't imagine there is much functional difference at this point.
>
> Tested-by: Jeremy Linton <jeremy.linton@arm.com>
>

I'll post a separate two-patch series which introduces -ENXIO as return value.

Guenter