From 7e5c603cba0823fd97456984f4cfc21c4c831b52 Mon Sep 17 00:00:00 2001
From: Aiman Rosli <muhammad.aiman.rosli@intel.com>
Date: Fri, 21 Jan 2022 02:53:24 +0800
Subject: [PATCH] MdeModulePkg/SdMmcPciHcDxe: Robust improvements for SD card
 1.8V switch

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.

Change is for Enabling OS boot from SD card through UEFI payload.

Signed-off-by: Aiman Rosli <muhammad.aiman.rosli@intel.com>
Reviewed-by: Hao A Wu <hao.a.wu@intel.com>
---
 MdeModulePkg/Bus/Pci/SdMmcPciHcDxe/SdDevice.c | 39 +++++++++++++++++--
 1 file changed, 36 insertions(+), 3 deletions(-)

diff --git a/MdeModulePkg/Bus/Pci/SdMmcPciHcDxe/SdDevice.c b/MdeModulePkg/Bus/Pci/SdMmcPciHcDxe/SdDevice.c
index 662f9f483c..f5a3607e47 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 +1299,13 @@ SdCardIdentification (
     return EFI_UNSUPPORTED;
   }
 
+  //
+  // 1.8V had failed in the previous run, forcing a retry with 3.3V instead
+  //
+  if (ForceVoltage33 == TRUE) {
+    S18r = FALSE;
+  }
+
   //
   // 5. Repeatly send Acmd41 with supply voltage window to the device.
   //    Note here we only support the cards complied with SD physical
@@ -1366,9 +1378,30 @@ SdCardIdentification (
 
       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;
+        //
+        // Delay 50 milliseconds in order for clock to stabilize, retry reading the SD_MMC_HC_PRESENT_STATE
+        //
+        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));
+          //
+          // Reset and reinitialize the slot before the 3.3V retry.
+          //
+          Status = SdMmcHcReset (Private, Slot);
+          if (EFI_ERROR (Status)) {
+            goto Error;
+          }
+
+          Status = SdMmcHcInitHost (Private, Slot);
+          if (EFI_ERROR (Status)) {
+            goto Error;
+          }
+
+          DEBUG ((DEBUG_ERROR, "SdCardIdentification: Switching to 1.8V failed, forcing a retry with 3.3V instead\n"));
+          ForceVoltage33 = TRUE;
+          goto Voltage33Retry;
+        }
       }
     }