two commits from glenn; see changelog

Docs/Changelog_sm-ssc.txt

@@ -16,11 +16,20 @@ sm-ssc v1.0 Release Candidate 2 | 201007xx
 
 20100717
 --------
+sm4svn:
+* r28385: Fix memory card port handling on newer kernels. There's got to be a
+  better way to parse out a USB device's connection path. [Glenn Maynard]
+* r28386: Fix partitioned USB devices not always being seen correctly due to
+  race condition with the kernel partition scan. The sleep was a hack to work
+  around this issue which doesn't work in all cases. [Glenn Maynard]
+
+sm-ssc:
 * Added Menu(Left/Right/Up/Down)(P1/P2) messages to ScreenOptions.
 * [ScreenSelectMusic] Add ChangeStepsWithGameButtons, PreviousDifficultyButton,
   and NextDifficultyButton metrics, allowing the themer to not have to use
   CodeDetector. [Daisuke Master]
 
+
 20100715
 --------
 * Fix spacing of various pump modes. [Daisuke Master]

src/arch/MemoryCard/MemoryCardDriverThreaded_Linux.cpp

@@ -3,6 +3,7 @@
 #include "RageLog.h"
 #include "RageUtil.h"
 #include "RageFile.h"
+#include "RageTimer.h"
 
 #include <cerrno>
 #include <fcntl.h>
@@ -129,27 +130,55 @@ void MemoryCardDriverThreaded_Linux::GetUSBStorageDevices( vector<UsbStorageDevi
 			RString sPath = sBlockDevicePath + sDevice + "/";
 			usbd.sSysPath = sPath;
 
-			/* Ignore non-removable devices. */
+			// Ignore non-removable devices.
 			RString sBuf;
 			if( !ReadFile( sPath + "removable", sBuf ) )
 				continue; // already warned
 			if( atoi(sBuf) != 1 )
 				continue;
 
+			/* The kernel isn't exposing all of /sys atomically, so we end up missing
+			 * the partition due to it not being shown yet. It won't show up until the
+			 * kernel has scanned the partition table, which can take a variable amount
+			 * of time, sometimes over a second. Watch for the "queue" sysfs directory,
+			 * which is created after this, to tell when partition directories are created. */
+			RageTimer WaitUntil;
+			WaitUntil += 5;
+			RString sQueueFilePath = usbd.sSysPath + "queue";
+			while(1)
+			{
+				if( WaitUntil.Ago() >= 0 )
+				{
+					LOG->Warn( "Timed out waiting for %s", sQueueFilePath.c_str() );
+					break;
+				}
 
-			/* HACK: The kernel isn't exposing all of /sys atomically, so we end up
+				if( access(usbd.sSysPath, F_OK) == -1 )
-			 * missing the partition due to it not being shown yet.  The kernel should
+				{
-			 * be exposing all of this atomically. */
+					LOG->Warn( "Block directory %s went away while we were waiting for %s",
-			usleep(50000);
+							usbd.sSysPath.c_str(), sQueueFilePath.c_str() );
+					break;
+				}
 
-			/* If the first partition device exists, eg. /sys/block/uba/uba1, use it. */
+				if( access(sQueueFilePath, F_OK) != -1 )
+					break;
+
+				usleep(10000);
+			}
+
+			// If the first partition device exists, eg. /sys/block/uba/uba1, use it.
 			if( access(usbd.sSysPath + sDevice + "1", F_OK) != -1 )
+			{
+				LOG->Trace("OK");
 				usbd.sDevice = "/dev/" + sDevice + "1";
+			}
 			else
+			{
+				LOG->Trace("error %s", strerror(errno));
 				usbd.sDevice = "/dev/" + sDevice;
+			}
 
-			/*
+			/* sPath/device should be a symlink to the actual device.  For USB
-			 * sPath/device should be a symlink to the actual device.  For USB
 			 * devices, it looks like this:
 			 *
 			 * device -> ../../devices/pci0000:00/0000:00:02.1/usb2/2-1/2-1:1.0
@@ -164,11 +193,12 @@ void MemoryCardDriverThreaded_Linux::GetUSBStorageDevices( vector<UsbStorageDevi
 			}
 			else
 			{
-				/*
+				/* The full path looks like:
-				 * The full path looks like
-				 *
 				 * ../../devices/pci0000:00/0000:00:02.1/usb2/2-2/2-2.1/2-2.1:1.0
 				 *
+				 * In newer kernels, it looks like:
+				 * ../../../3-2.1:1.0
+				 *
 				 * Each path element refers to a new hop in the chain.
 				 *  "usb2" = second USB host
 				 *  2-            second USB host,
@@ -177,15 +207,20 @@ void MemoryCardDriverThreaded_Linux::GetUSBStorageDevices( vector<UsbStorageDevi
 				 *       .2       ... port 2 on the next hub ...
 				 * 
 				 * We want the bus number and the port of the last hop.  The level is
-				 * the number of hops.
+				 * the number of hops. */
-				 */
 				szLink[iRet] = 0;
 				vector<RString> asBits;
 				split( szLink, "/", asBits );
 
-				if( strstr( szLink, "usb" ) != NULL )
+				RString sHostPort = asBits[asBits.size()-1];
+				if( !sHostPort.empty() )
 				{
-					RString sHostPort = asBits[asBits.size()-2];
+					// Strip off the endpoint information after the colon.
+					size_t pos = sHostPort.find(':');
+					if( pos != string::npos )
+						sHostPort.erase( pos );
+					
+					// sHostPort is eg. 2-2.1.
 					sHostPort.Replace( "-", "." );
 					asBits.clear();
 					split( sHostPort, ".", asBits );
@@ -282,7 +317,7 @@ void MemoryCardDriverThreaded_Linux::GetUSBStorageDevices( vector<UsbStorageDevi
 				usbd.sProduct.c_str(), usbd.sSerial.c_str(), usbd.sOsMountDir.c_str() );
 	}
 
-	/* Remove any devices that we couldn't find a mountpoint for. */
+	// Remove any devices that we couldn't find a mountpoint for.
 	for( unsigned i=0; i<vDevicesOut.size(); i++ )
 	{
 		UsbStorageDevice& usbd = vDevicesOut[i];