-----Original Message----- From: Jean-Christophe PLAGNIOL-VILLARD [mailto:plagnioj@jcrosoft.com] Sent: Thursday, August 20, 2009 4:07 AM To: Simon Kagstrom Cc: Prafulla Wadaskar; U-Boot ML; Prabhanjan Sarnaik; Ashish Karkare Subject: Re: [U-Boot] [PATCH] arm:kirkwood See to it that sent data is 8-byte aligned
On 12:48 Tue 18 Aug , Simon Kagstrom wrote:
Thanks for the review Prafulla!
On Tue, 18 Aug 2009 03:12:07 -0700 Prafulla Wadaskar prafulla@marvell.com wrote:
v2: Malloc send buffer (comment from Stefan Roese)
Malloc will always be an overhead.
It's only allocated once (the first time a non-aligned buffer is passed), so the overhead is minimal.
I strongly recommend- we should pass aligned buffers from
upper layers
to avoid such rework in all low level drivers, (few are already aligned).
We could put the same fix in eth_send instead. Then the
issue is really
just how we know what alignment requirement to go for. I guess one could add a field to the eth_device structure to store this and then fixup all drivers to supply this.
If the rest of you thinks this is a good idea, I can cook
up a patch.
Opinions?
some drivers would also have the possibility to have multiple receive buffer specially when you use dma so IMHO it make more sense to let each drivers handle it itself
In that case it makes more sense to implement this even for rx path too in upper layer. We should always push common functionalities to upper layers And this is very generic need for any driver that uses dma for transfers
Regards.. Prafulla . .
Best Regards, J.