Re: [edk2-devel] [PATCH v3 1/1] MdeModulePkg/XhciDxe: Fix Broken Timeouts

["Henz, Patrick" <patrick.henz@hpe.com>]

Hi Jess,

Thank you for reporting this, it's certainly a bug. I'm planning to implement a fix.

Thanks,
Patrick Henz

-----Original Message-----
From: Jessica Clarke <jrtc27@jrtc27.com> 
Sent: Wednesday, June 7, 2023 4:38 PM
To: Henz@mx0a-002e3701.pphosted.com; Henz, Patrick <patrick.henz@hpe.com>; devel@edk2.groups.io
Subject: Re: [edk2-devel] [PATCH v3 1/1] MdeModulePkg/XhciDxe: Fix Broken Timeouts

On Wed, Sep 23, 2020 at 08:36 PM, Henz, Patrick wrote:

>
> From: Patrick Henz <patrick.henz@hpe.com>
> 
> REF:INVALID URI REMOVED
> g.cgi?id=2948__;!!NpxR!iZG1WFNYYsLpsDRVpII4yD3VcV3qTNWYYBKIkjOpmdsJq4e
> cXWzlnbRiJf9vTEZUUu73BuQmhJJwUHocWQ$
> 
> Timeouts in the XhciDxe driver are taking longer than expected due to 
> the timeout loops not accounting for code execution time. As en 
> example, 5 second timeouts have been observed to take around 36 
> seconds to complete.
> Use SetTimer and Create/CheckEvent from Boot Services to determine 
> when timeout occurred.

This strategy doesn't work during ExitBootServices, as called from XhcExitBootService via XhcHaltHC. The net result is that, if the XHCI controller fails to halt upon clearing R/S, EDK2 hangs in an infinite loop (something I just had the joy of debugging).

Jess