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
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