From: Claudiu Manoil <claudiu.manoil@freescale.com>
To: Kevin Hao <haokexin@gmail.com>, <netdev@vger.kernel.org>
Cc: David Miller <davem@davemloft.net>
Subject: Re: [PATCH net v2] gianfar: Fix dma check map error when DMA_API_DEBUG is enabled
Date: Thu, 11 Dec 2014 19:05:54 +0200 [thread overview]
Message-ID: <5489CEF2.5090208@freescale.com> (raw)
In-Reply-To: <1418278121-20209-1-git-send-email-haokexin@gmail.com>
On 12/11/2014 8:08 AM, Kevin Hao wrote:
> We need to use dma_mapping_error() to check the dma address returned
> by dma_map_single/page(). Otherwise we would get warning like this:
> WARNING: at lib/dma-debug.c:1140
> Modules linked in:
> CPU: 0 PID: 0 Comm: swapper/0 Not tainted 3.18.0-rc2-next-20141029 #196
> task: c0834300 ti: effe6000 task.ti: c0874000
> NIP: c02b2c98 LR: c02b2c98 CTR: c030abc4
> REGS: effe7d70 TRAP: 0700 Not tainted (3.18.0-rc2-next-20141029)
> MSR: 00021000 <CE,ME> CR: 22044022 XER: 20000000
>
> GPR00: c02b2c98 effe7e20 c0834300 00000098 00021000 00000000 c030b898 00000003
> GPR08: 00000001 00000000 00000001 749eec9d 22044022 1001abe0 00000020 ef278678
> GPR16: ef278670 ef278668 ef278660 070a8040 c087f99c c08cdc60 00029000 c0840d44
> GPR24: c08be6e8 c0840000 effe7e78 ef041340 00000600 ef114e10 00000000 c08be6e0
> NIP [c02b2c98] check_unmap+0x51c/0x9e4
> LR [c02b2c98] check_unmap+0x51c/0x9e4
> Call Trace:
> [effe7e20] [c02b2c98] check_unmap+0x51c/0x9e4 (unreliable)
> [effe7e70] [c02b31d8] debug_dma_unmap_page+0x78/0x8c
> [effe7ed0] [c03d1640] gfar_clean_rx_ring+0x208/0x488
> [effe7f40] [c03d1a9c] gfar_poll_rx_sq+0x3c/0xa8
> [effe7f60] [c04f8714] net_rx_action+0xc0/0x178
> [effe7f90] [c00435a0] __do_softirq+0x100/0x1fc
> [effe7fe0] [c0043958] irq_exit+0xa4/0xc8
> [effe7ff0] [c000d14c] call_do_irq+0x24/0x3c
> [c0875e90] [c00048a0] do_IRQ+0x8c/0xf8
> [c0875eb0] [c000ed10] ret_from_except+0x0/0x18
>
> For TX, we need to unmap the pages which has already been mapped and
> free the skb before return.
>
> For RX, move the dma mapping and error check to gfar_new_skb(). We
> would reuse the original skb in the rx ring when either allocating
> skb failure or dma mapping error.
>
> Signed-off-by: Kevin Hao <haokexin@gmail.com>
> ---
> v2: Just update the RX path to reuse the original skb when dma mapping error
> occurs as suggested by David.
>
Very nice refactoring of gfar_new_skb(), removing gfar_new_rxbdp() in
the process. (Did not have the time to test it yet.)
Thanks.
Reviewed-by: Claudiu Manoil <claudiu.manoil@freescale.com>
next prev parent reply other threads:[~2014-12-11 17:38 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-12-05 10:37 [PATCH 0/2] DMA API usage fixes in gianfar Arseny Solokha
2014-12-05 10:37 ` [PATCH 1/2] gianfar: handle map error in gfar_new_rxbdp() Arseny Solokha
2014-12-09 20:37 ` David Miller
2014-12-05 10:37 ` [PATCH 2/2] gianfar: handle map error in gfar_start_xmit() Arseny Solokha
2014-12-05 12:42 ` Denis Kirjanov
2014-12-05 14:51 ` Claudiu Manoil
2014-12-09 20:39 ` David Miller
2014-12-10 11:03 ` David Laight
2014-12-05 14:48 ` [PATCH 0/2] DMA API usage fixes in gianfar Claudiu Manoil
2014-12-09 14:24 ` [PATCH net] gianfar: Fix dma check map error when DMA_API_DEBUG is enabled Claudiu Manoil
2014-12-10 18:13 ` David Miller
2014-12-11 2:06 ` Kevin Hao
2014-12-11 6:08 ` [PATCH net v2] " Kevin Hao
2014-12-11 17:05 ` Claudiu Manoil [this message]
2014-12-11 19:27 ` David Miller
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=5489CEF2.5090208@freescale.com \
--to=claudiu.manoil@freescale.com \
--cc=davem@davemloft.net \
--cc=haokexin@gmail.com \
--cc=netdev@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.