[edk2-devel] [PATCH edk2-platforms v2 0/4] Provide XHCI USB controller only for newer hardware

Marcin Juszkiewicz marcin.juszkiewicz at linaro.org
Mon Oct 16 10:06:26 UTC 2023


Platform version 0.3 introduced XHCI USB controller instead of EHCI one.
But we did it in a way that there is no in-EDK2 check for platform
version (XHCI is always given).

This behaviour works with Linux as it complains about being unable to
initialize EHCI and goes on. Free/Net/Open BSD systems hang in such
situation.

Now we check are we on Platform Version 0.3 at least and then initialize
XHCI controller. Otherwise we disable it's node in DSDT table.

I checked several ways to handle the situation. 

SSDT overlay enabling with LocateAndInstallAcpiFromFvConfitional() was
first one but this function had only DBG2 and FACP tables.

Then looked at trying to detect XHCI from _STA method. But this is
sysbus device which is there or not without way to discover it.

Next attempt was to have variable in DSDT and to use it in _STA. Too
much trouble.

Then looked again at code from
Ampere/JadePkg/Drivers/AcpiPlatformDxe/AcpiDsdt.c and noticed
UpdateStatusMethodObject() function. Copied some code and it worked.

Booting OpenBSD reminded me to update table checksum.

---
Changes in v2:
- XHCI initialized only on PlatVer 0.3+
- XHCI disabled in DSDT for older platforms
- no SSDT overlays for EHCI/XHCI
- no EHCI at all (it does not work anyway)
- no Pcd renaming

---
Marcin Juszkiewicz (4):
      SbsaQemu: introduce macro to compare platform version
      SbsaQemu: add AcpiLib
      SbsaQemu: initialize XHCI only if it exists
      SbsaQemu: disable XHCI in DSDT if not present

 Platform/Qemu/SbsaQemu/SbsaQemu.dsc                  |  2 +
 .../Drivers/SbsaQemuAcpiDxe/SbsaQemuAcpiDxe.inf      |  4 +
 .../IndustryStandard/SbsaQemuPlatformVersion.h       | 25 ++++++
 .../Drivers/SbsaQemuAcpiDxe/SbsaQemuAcpiDxe.c        | 93 ++++++++++++++++++++
 .../SbsaQemuPlatformDxe/SbsaQemuPlatformDxe.c        | 47 +++++-----
 5 files changed, 149 insertions(+), 22 deletions(-)
---
base-commit: 06f6274d56422084281886fad447ab117fd0e487
change-id: 20231013-ehci-xhci-fix-c529356a7a8f

Best regards,
-- 
Marcin Juszkiewicz <marcin.juszkiewicz at linaro.org>



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