Re: [PATCH v6 2/5] PCI: brcmstb: Configure HW CLKREQ# mode appropriate for downstream device

From: Sam Edwards
Date: Tue Sep 05 2023 - 16:24:58 EST


On 6/23/23 08:40, Jim Quinlan wrote:

Hi Jim,

As I understand, the issue that this patch fixes can be difficult to trigger reliably. So I'll report that the abort occurs 100% of the time on a Compute Module 4, installed in slot 3 of a Turing Pi 2 cluster board, when a bootloader (U-Boot, in my case) is in the boot path. The third slot of the TP2 board connects to an ASM1061 chip with the CLKREQ# line left floating. I do not know why the bootloader is necessary for the crash to occur; I suspect it's timing-related.

With this patch applied to my kernel, my observed crash rate goes from 100% to 0%, so:

Signed-off-by: Jim Quinlan <james.quinlan@xxxxxxxxxxxx>
Tested-by: Florian Fainelli <f.fainelli@xxxxxxxxx>
Tested-by: Cyril Brulebois <cyril@xxxxxxxxxxx>
Tested-by: Sam Edwards <CFSworks@xxxxxxxxx>

Many thanks,
Sam