From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <001c01c28b4b$28665b80$4f158a86@default> From: "Hans Feldt" To: Cc: , , References: Subject: Re: [PATCH] arch/ppc/8xx_io/enet.c, version 2 Date: Wed, 13 Nov 2002 20:30:41 +0100 MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Sender: owner-linuxppc-embedded@lists.linuxppc.org List-Id: ----- Original Message ----- From: Joakim Tjernlund > You may be right, perhaps one must invalidate the whole buffer before giving it > to the CPM/DMA. Suppose you reuse a buffer which has been modified before it > was freed and the dcache must write back data to free up space and the buffer, > which now is owned by the CPM, get written to. I beleive this could happen. Since IP does not perform checksumming but relies on the link (don't know this really) in that matter, I guess the application could get wrong data... > I have not seen any corrupted packets and you are the first to report > any problems. Did you run any data integrity tests? > What modifications have you done? I haven't used your driver patch. I used the __idea__ of delaying the invalidate to the point where you know how much has been received. This was in an RTOS ATM driver for a 405. An integrity test showed that some few packets was wrong. Data was changed by means of cache lines. > What CPU? > Post the driver please. Irrelevant, non-linux Cheers, Hans ** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/