Hi,

Shawn Guo writes:

On Fri, Jan 14, 2011 at 08:52:23AM +0100, Uwe Kleine-K?nig wrote:

quoted

On Fri, Jan 14, 2011 at 01:48:40PM +0800, Shawn Guo wrote:

quoted

Hi Uwe,

On Thu, Jan 13, 2011 at 03:48:05PM +0100, Uwe Kleine-K?nig wrote:

[...]

quoted

quoted

+/* Controller is ENET-MAC */
+#define FEC_QUIRK_ENET_MAC           (1 << 0)

does this really qualify to be a quirk?

My understanding is that ENET-MAC is a type of "quirky" FEC
controller.

quoted

quoted

+/* Controller needs driver to swap frame */
+#define FEC_QUIRK_SWAP_FRAME         (1 << 1)

IMHO this is a bit misnamed.  FEC_QUIRK_NEEDS_BE_DATA or similar would
be more accurate.

When your make this change, you may want to pick a better name for
function swap_buffer too.

[...]

quoted

quoted

+static void *swap_buffer(void *bufaddr, int len)
+{
+     int i;
+     unsigned int *buf = bufaddr;
+
+     for (i = 0; i < (len + 3) / 4; i++, buf++)
+             *buf = cpu_to_be32(*buf);

if len isn't a multiple of 4 this accesses bytes behind len.  Is this
generally OK here?  (E.g. because skbs always have a length that is a
multiple of 4?)

The len may not be a multiple of 4.  But I believe bufaddr is always
a buffer allocated in a length that is a multiple of 4, and the 1~3
bytes exceeding the len very likely has no data that matters.  But
yes, it deserves a safer implementation.

Did you test what happens if bufaddr isn't aligned?  Does it work at all
then?

I see many calls passing a len that is not a multiple of 4, but it
works good.

That does not prove anything, actually.

Anyway "bufaddr isn't aligned" != "len is not a multiple of 4".
Is there any guarantee that the function cannot be called with a
non-aligned buffer address?


Lothar Wa?mann
-- 
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