One little change to the comment is needed.  See below

Don

On Wed, 2015-03-18 at 20:10 +0000, Markos Chandras wrote:

On a MIPS Malta board, tons of fifo underflow errors have been observed
when using u-boot as bootloader instead of YAMON. The reason for that
is that YAMON used to set the pcnet device to SRAM mode but u-boot does
not. As a result, the default Tx threshold (64 bytes) is now too small to
keep the fifo relatively used and it can result to Tx fifo underflow errors.
As a result of which, it's best to setup the SRAM on supported controllers
so we can always use the NOUFLO bit.

+	/*
+	 * The Am79C973/Am79C975 controllers come with 12K of SRAM
+	 * which we can use for the Tx/Rx buffers but most importantly,
+	 * the use of SRAM allow us to use the BCR18:NOUFLO bit to avoid
+	 * Tx fifo underflows.
+	 */
+	if (sram) {
+		/*
+		 * The SRAM is being configured in two steps. First we
+		 * set the SRAM size in the BCR25:SRAM_SIZE bits. According
+		 * to the datasheet, each bit corresponds to a 512-byte
+		 * page so we can have at most 24 pages. The SRAM_SIZE
+		 * corresponds holds the value of the upper 8 bits of
+		 * the 16-bit SRAM size. The low 8-bits start at 0x00
+		 * and end at 0xff. So the address range is from 0x0000
+		 * up to 0x17ff. Therefore, the SRAM_SIZE is set to 0x17.
+		 * The next step is to set the BCR24:SRAM_BND midway through
+		 * so the Tx and Rx buffers can share the SRAM equally.
+		 */

The comment specifies BCR24 but the code is changing BCR26 which matches
the documentation.  Please correct the comment to avoid confusion.

+		a->write_bcr(ioaddr, 25, 0x17);
+		a->write_bcr(ioaddr, 26, 0xc);
+		/* And finally enable the NOUFLO bit */