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MdeModulePkg/XhciPei:1ms delay before access MMIO reg during reset 

Some XHCI host controllers require to have extra 1ms delay before
accessing any MMIO register during HC reset.

As this delay is not defined by XHCI spec, we use this workaround
to fix the issue.

Cc: Star Zeng <star.zeng@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Feng Tian <feng.tian@intel.com>
Reviewed-by: Star Zeng <star.zeng@intel.com>
This commit is contained in:
Feng Tian 2016-09-14 09:48:40 +08:00
parent dbe10619bc
commit 1f87985ab7
1 changed files with 6 additions and 0 deletions
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6
MdeModulePkg/Bus/Pci/XhciPei/XhcPeim.c
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@ -407,6 +407,12 @@ XhcPeiResetHC (
}
XhcPeiSetOpRegBit (Xhc, XHC_USBCMD_OFFSET, XHC_USBCMD_RESET);
//
// Some XHCI host controllers require to have extra 1ms delay before accessing any MMIO register during reset.
// Otherwise there may have the timeout case happened.
// The below is a workaround to solve such problem.
//
MicroSecondDelay (1000);
Status = XhcPeiWaitOpRegBit (Xhc, XHC_USBCMD_OFFSET, XHC_USBCMD_RESET, FALSE, Timeout);
ON_EXIT:
DEBUG ((EFI_D_INFO, "XhcPeiResetHC: %r\n", Status));