Re: net: phy: realtek: regression, kernel null pointer dereference

From: Vicente Bergas
Date: Sat May 11 2019 - 11:18:05 EST

On Saturday, May 11, 2019 5:08:19 PM CEST, Andrew Lunn wrote:
On Sat, May 11, 2019 at 04:46:40PM +0200, Vicente Bergas wrote:
On Friday, May 10, 2019 10:28:06 PM CEST, Heiner Kallweit wrote:
On 10.05.2019 17:05, Vicente Bergas wrote:
there is a regression on linux v5.1-9573-gb970afcfcabd with a kernel null
pointer dereference.
The issue is the commit f81dadbcf7fd067baf184b63c179fc392bdb226e
net: phy: realtek: Add rtl8211e rx/tx delays config ...
The page operation callbacks are missing in the RTL8211E driver.
I just submitted a fix adding these callbacks to few Realtek PHY drivers
including RTl8211E. This should fix the issue.

Hello Heiner,
just tried your patch and indeed the NPE is gone. But still no network...
The MAC <-> PHY link was working before, so, maybe the rgmii delays are not
correctly configured.

Hi Vicente

What phy-mode do you have in device tree? Have you tried the others?



Hi Andrew,
it is configured as in the vanilla kernel:
,that is,
phy-mode = "rgmii";
There are also these configuration items:
tx_delay = <0x28>;
rx_delay = <0x11>;

Instead of going the trial-and-error way, please, can you suggest a
probably good configuration?