On Wednesday 23 August 2006 18:55, Jeff Garzik wrote: > Michael Buesch wrote: > >> Please note that this test is only compile tested, as > >> I don't have a b44 device. > > >> @@ -2055,7 +2055,7 @@ > >> u16 *ptr = (u16 *) data; > >> > >> for (i = 0; i < 128; i += 2) > >> - ptr[i / 2] = readw(bp->regs + 4096 + i); > >> + ptr[i / 2] = cpu_to_le16(readw(bp->regs + 4096 + i)); > >> > > > This looks a bit weird. readw() swaps on big-endian already. > > This patch swaps each word -again- on big-endian, even though the only > user of the eeprom data is the get-invariants code that reads the MAC > address and phy id.
Yeah. But look at where the data is stored. The data ends up in a _byte_ array. A byte array is litte endian (little end first). array[0] is low and array[1] is high. Look at the pointer cast above: u16 *ptr = (u16 *) data; We store data in _cpu_ order in this byte array. That's wrong. If we are on a little endian machine, that's ok. But if we are on a big endian machine, this will write bytes swapped. LE will result in an array: ABABABABABABAB BE will result in an array: BABABABABABABA But only the first result (LE) is valid, because that's expected later when interpreting the data. -- Greetings Michael. - To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
