[U-Boot] generic mmc bug in reading sd card capacity

victor victor at keyasic.com
Fri Nov 2 08:12:52 CET 2012


Hi All,

Accord to SD spec 2.0, the formula to find out sd card capacity is:

memory capacity = (C_SIZE+1) * 512K byte 
 	and
C_SIZE  is from CSD [69:48]

Thus, the code in generic mmc is wrong for the high capacity sd card. My
patch is below.

Thanks,
victor

--- mmc.c	2012-10-09 02:20:28.000000000 +0800
+++ mmc.c.victor	2012-11-02 15:07:16.949207266 +0800
@@ -1068,17 +1104,26 @@
 		mmc->write_bl_len = 1 << ((cmd.response[3] >> 22) & 0xf);
 
 	if (mmc->high_capacity) {
-		csize = (mmc->csd[1] & 0x3f) << 16
-			| (mmc->csd[2] & 0xffff0000) >> 16;
-		cmult = 8;
+		//csize = (mmc->csd[1] & 0x3f) << 16
+		//	| (mmc->csd[2] & 0xffff0000) >> 16;
+		//cmult = 8;
+                csize = (mmc->csd[2] & 0x3f) << 16
+                      | (mmc->csd[1] & 0xffff0000) >> 16;
 	} else {
 		csize = (mmc->csd[1] & 0x3ff) << 2
 			| (mmc->csd[2] & 0xc0000000) >> 30;
 		cmult = (mmc->csd[2] & 0x00038000) >> 15;
 	}
 
-	mmc->capacity = (csize + 1) << (cmult + 2);
-	mmc->capacity *= mmc->read_bl_len;
+	if (mmc->high_capacity) {
+		mmc->capacity = (csize + 1) * 512 * 1024;
+	} else {
+		mmc->capacity = (csize + 1) << (cmult + 2);
+		mmc->capacity *= mmc->read_bl_len;
+	}


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