From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jarek Poplawski Subject: Re: [PATCH] sky2: receive dma mapping error handling Date: Sun, 31 Jan 2010 23:18:35 +0100 Message-ID: <20100131221835.GA3317@del.dom.local> References: <20100128223447.GC3109@del.dom.local> <4B621316.8070308@majjas.com> <20100128225621.GD3109@del.dom.local> <4B6216B9.1010802@majjas.com> <20100128153643.0fca3c51@nehalam> <4B645EF4.4050701@majjas.com> <20100131003449.GA11935@del.dom.local> <4B650D53.2010607@majjas.com> <4B65D0F9.2020602@majjas.com> <4B65FD12.7090101@majjas.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Stephen Hemminger , David Miller , akpm@linux-foundation.org, flyboy@gmail.com, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, Michael Chan , Don Fry , Francois Romieu , Matt Carlson To: Michael Breuer Return-path: Content-Disposition: inline In-Reply-To: <4B65FD12.7090101@majjas.com> Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org On Sun, Jan 31, 2010 at 04:58:42PM -0500, Michael Breuer wrote: > On 1/31/2010 1:50 PM, Michael Breuer wrote: > >On 1/30/2010 11:55 PM, Michael Breuer wrote: > >>On 01/30/2010 07:34 PM, Jarek Poplawski wrote: > >>> > >>>Could you try the patch below to show maybe some other users of > >>>dma-debug entries? > >>> > >>>Jarek P. > >>>--- > >>> > >>With the default # entries & dma_debug_driver=sky2: > >> > >>6:00 is eth0 & 4:00 is eth1. > >> > >>Jan 30 23:53:14 mail kernel: DMA-API: 0000:06:00.0: entries: 31961 > >>... > >> > >I put a printk as a third else case in sky2_tx_unmap. Looks like > >the issue is that a large number (perhaps all) calls to > >sky2_tx_unmap have re->flags set to neither TX_MAP_SINGLE or > >TX_MAP_PAGE. Thus the elements are never being unmapped. > > > >I suspect that the system collapses when using DMAR sooner than if > >not using DMAR. Probably some hardware limitation on the number of > >mapped elements that is less than the software limitation. I don't > >see at present how a ring element can ever get to this code > >without re->flags being set to one or the other. > > > > > Put some more debugging code in... re->flags is always NULL upon > entry to sky2_tx_unmap. > Yes, good point! Could you try if this patch can fix it. (not compiled) Thanks, Jarek P. --- drivers/net/sky2.c | 10 +++++++--- 1 files changed, 7 insertions(+), 3 deletions(-) diff --git a/drivers/net/sky2.c b/drivers/net/sky2.c index d760650..3437917 100644 --- a/drivers/net/sky2.c +++ b/drivers/net/sky2.c @@ -1025,9 +1025,10 @@ static void sky2_prefetch_init(struct sky2_hw *hw, u32 qaddr, static inline struct sky2_tx_le *get_tx_le(struct sky2_port *sky2, u16 *slot) { struct sky2_tx_le *le = sky2->tx_le + *slot; - struct tx_ring_info *re = sky2->tx_ring + *slot; + struct tx_ring_info *re; *slot = RING_NEXT(*slot, sky2->tx_ring_size); + re = sky2->tx_ring + *slot; re->flags = 0; re->skb = NULL; le->ctrl = 0; @@ -1036,13 +1037,16 @@ static inline struct sky2_tx_le *get_tx_le(struct sky2_port *sky2, u16 *slot) static void tx_init(struct sky2_port *sky2) { - struct sky2_tx_le *le; + struct sky2_tx_le *le = sky2->tx_le; + struct tx_ring_info *re = sky2->tx_ring; sky2->tx_prod = sky2->tx_cons = 0; sky2->tx_tcpsum = 0; sky2->tx_last_mss = 0; - le = get_tx_le(sky2, &sky2->tx_prod); + re->flags = 0; + re->skb = NULL; + le->ctrl = 0; le->addr = 0; le->opcode = OP_ADDR64 | HW_OWNER; sky2->tx_last_upper = 0;