This changes is by adding 50ms delay during voltage switching from 3.3V to 1.8V,
plus adding a goto Voltage33Retry for 3.3V checking and retrying.

Signed-off-by: Aiman Rosli <muhammad.aiman.rosli@...>
---
MdeModulePkg/Bus/Pci/SdMmcPciHcDxe/SdDevice.c | 23 ++++++++++++++++---
1 file changed, 20 insertions(+), 3 deletions(-)

diff --git a/MdeModulePkg/Bus/Pci/SdMmcPciHcDxe/SdDevice.c b/MdeModulePkg/Bus/Pci/SdMmcPciHcDxe/SdDevice.c
index 662f9f483c..527fe7dc20 100644
--- a/MdeModulePkg/Bus/Pci/SdMmcPciHcDxe/SdDevice.c
+++ b/MdeModulePkg/Bus/Pci/SdMmcPciHcDxe/SdDevice.c
@@ -1213,9 +1213,14 @@ SdCardIdentification (
UINT32 PresentState;
UINT8 HostCtrl2;
UINTN Retry;
+ BOOLEAN ForceVoltage33;
+
+ ForceVoltage33 = FALSE;

PciIo = Private->PciIo;
PassThru = &Private->PassThru;
+
+Voltage33Retry:
//
// 1. Send Cmd0 to the device
//
@@ -1294,6 +1299,14 @@ SdCardIdentification (
return EFI_UNSUPPORTED;
}

+ //
+ // 1.8V had failed in the previous run, forcing a retry with 3.3V instead
+ //
+ if (ForceVoltage33 == TRUE) {
+ S18r = FALSE;
+ ForceVoltage33 = FALSE;
+ }
+
//
// 5. Repeatly send Acmd41 with supply voltage window to the device.
// Note here we only support the cards complied with SD physical
@@ -1362,13 +1375,17 @@ SdCardIdentification (
goto Error;
}

- gBS->Stall (1000);
+ // Workaround to add a delay of 50 ms in order for clock to stabilize before turning on the SD card again.
+ gBS->Stall (50000);

SdMmcHcRwMmio (PciIo, Slot, SD_MMC_HC_PRESENT_STATE, TRUE, sizeof (PresentState), &PresentState);
if (((PresentState >> 20) & 0xF) != 0xF) {
DEBUG ((DEBUG_ERROR, "SdCardIdentification: SwitchVoltage fails with PresentState = 0x%x, It should be 0xF\n", PresentState));
- Status = EFI_DEVICE_ERROR;
- goto Error;
+ Status = SdMmcHcReset (Private, Slot);
+ Status = SdMmcHcInitHost (Private, Slot);
+ ForceVoltage33 = TRUE;
+ DEBUG ((DEBUG_ERROR, "SdCardIdentification: Switching to 1.8V had failed in the previous run, forcing a retry with 3.3V instead\n"));
+ goto Voltage33Retry;
}
}

--
2.34.1.windows.1