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

From: Guenter Roeck
Date: Wed Aug 26 2015 - 16:07:23 EST


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@xxxxxxxxxxxx>
---
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@xxxxxxx>


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

Guenter

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