lkml.org 
[lkml]   [2014]   [Jan]   [14]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
SubjectRe: build_skb() and data corruption
Date
On Tuesday 14 January 2014, Jonas Jensen wrote:
> Thanks for the replies, you led me to a new solution,
>
>
> I now think build_skb() is not the right choice, my motivation for
> using it in the first place, that I thought it meant getting away with
> not copying memory.
>
> build_skb() is replaced by netdev_alloc_skb_ip_align() and memcpy()
> (derived from drivers/net/ethernet/realtek/r8169.c).
>
> Read errors are gone, even without syncing DMA. Is it a good idea to
> do it anyway, i.e. leave calls to dma_sync_single_* in?

The calls to dma_sync_single_* in the moxart_rx() function are needed.
The call to arm_dma_ops.sync_single_for_device() in
moxart_mac_setup_desc_ring() is wrong, because the buffer is already
owned by the device at that point (just after dma_map_single), and
because you should use the official dma_* api rather than using
the arm_dma_ops struct.

Arnd


\
 
 \ /
  Last update: 2014-01-14 17:41    [W:0.053 / U:0.752 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site