From 6e50f53d7cba30d3ef5170d8479c0e356ee03927 Mon Sep 17 00:00:00 2001
From: Natalia Portillo <claunia@claunia.com>
Date: Sat, 11 Dec 2021 19:48:34 +0000
Subject: [PATCH] When dumping an SD/MMC card try to detect if OS buffered
 reads are failing, and max readable blocks using sequential commands, and
 downgrade accordingly. Now also detects cards that are totally unreadable.

---
 Aaru.Core/Devices/Dumping/Dump.cs          |  2 +-
 Aaru.Core/Devices/Dumping/SecureDigital.cs | 74 ++++++++++++++++++++++
 2 files changed, 75 insertions(+), 1 deletion(-)

diff --git a/Aaru.Core/Devices/Dumping/Dump.cs b/Aaru.Core/Devices/Dumping/Dump.cs
index d2f1658cc..be7454c8d 100644
--- a/Aaru.Core/Devices/Dumping/Dump.cs
+++ b/Aaru.Core/Devices/Dumping/Dump.cs
@@ -93,7 +93,7 @@ namespace Aaru.Core.Devices.Dumping
         readonly DumpSubchannel             _subchannel;
         readonly bool                       _titleKeys;
         readonly bool                       _trim;
-        readonly bool                       _useBufferedReads;
+        bool                                _useBufferedReads;
         bool                                _aborted;
         AaruContext                         _ctx;   // Main database context
         Database.Models.Device              _dbDev; // Device database entry
diff --git a/Aaru.Core/Devices/Dumping/SecureDigital.cs b/Aaru.Core/Devices/Dumping/SecureDigital.cs
index a6e3559a5..13445bea4 100644
--- a/Aaru.Core/Devices/Dumping/SecureDigital.cs
+++ b/Aaru.Core/Devices/Dumping/SecureDigital.cs
@@ -313,6 +313,80 @@ namespace Aaru.Core.Devices.Dumping
                 }
             }
 
+            if(_useBufferedReads && blocksToRead > 1 && !supportsCmd23)
+            {
+                while(true)
+                {
+                    error = _dev.BufferedOsRead(out cmdBuf, 0, blockSize * blocksToRead,
+                                                out duration);
+
+                    if(error)
+                        blocksToRead /= 2;
+
+                    if(!error ||
+                       blocksToRead == 1)
+                        break;
+
+                    // Device is in timeout, reopen to reset
+                    if(_dev.LastError == 110)
+                        sense = _dev.ReOpen();
+                }
+
+                if(error)
+                {
+                    UpdateStatus?.Invoke("Buffered OS reads are not working, trying direct commands.");
+                    _dumpLog.WriteLine("Buffered OS reads are not working, trying direct commands.");
+                    blocksToRead      = 1;
+                    _useBufferedReads = false;
+                }
+            }
+
+            if(!_useBufferedReads && blocksToRead > 1 && !supportsCmd23)
+            {
+                while(true)
+                {
+                    error = _dev.ReadMultipleUsingSingle(out cmdBuf, out _, 0, blockSize, blocksToRead,
+                                                         byteAddressed, timeout, out duration);
+
+                    if(error)
+                        blocksToRead /= 2;
+
+                    // Device is in timeout, reopen to reset
+                    if(_dev.LastError == 110)
+                        sense = _dev.ReOpen();
+
+                    if(!error ||
+                       blocksToRead == 1)
+                        break;
+                }
+
+                if(error)
+                {
+                    _dumpLog.WriteLine("ERROR: Cannot get blocks to read, device error {0}.", _dev.LastError);
+
+                    StoppingErrorMessage?.
+                        Invoke($"Device error {_dev.LastError} trying to guess ideal transfer length.");
+
+                    return;
+                }
+            }
+
+            if(blocksToRead == 1)
+            {
+                error = _dev.ReadSingleBlock(out cmdBuf, out _, 0, blockSize, byteAddressed, timeout,
+                                             out duration);
+
+                if(error)
+                {
+                    _dumpLog.WriteLine("ERROR: Could not read from device, device error {0}.", _dev.LastError);
+
+                    StoppingErrorMessage?.
+                        Invoke($"Device error {_dev.LastError} trying to read from device.");
+
+                    return;
+                }
+            }
+
             if(supportsCmd23 || blocksToRead == 1)
             {
                 UpdateStatus?.Invoke($"Device can read {blocksToRead} blocks at a time.");