From 48330e08fa168395b9fd9f369f06cca1df204361 Mon Sep 17 00:00:00 2001 From: Soren Brinkmann Date: Tue, 4 Mar 2014 08:46:40 -0800 Subject: [PATCH] net: macb: DMA-unmap full rx-buffer When allocating RX buffers a fixed size is used, while freeing is based on actually received bytes, resulting in the following kernel warning when CONFIG_DMA_API_DEBUG is enabled: WARNING: CPU: 0 PID: 0 at lib/dma-debug.c:1051 check_unmap+0x258/0x894() macb e000b000.ethernet: DMA-API: device driver frees DMA memory with different size [device address=0x000000002d170040] [map size=1536 bytes] [unmap size=60 bytes] Modules linked in: CPU: 0 PID: 0 Comm: swapper/0 Not tainted 3.14.0-rc3-xilinx-00220-g49f84081ce4f #65 [] (unwind_backtrace) from [] (show_stack+0x10/0x14) [] (show_stack) from [] (dump_stack+0x7c/0xc8) [] (dump_stack) from [] (warn_slowpath_common+0x60/0x84) [] (warn_slowpath_common) from [] (warn_slowpath_fmt+0x2c/0x3c) [] (warn_slowpath_fmt) from [] (check_unmap+0x258/0x894) [] (check_unmap) from [] (debug_dma_unmap_page+0x64/0x70) [] (debug_dma_unmap_page) from [] (gem_rx+0x118/0x170) [] (gem_rx) from [] (macb_poll+0x24/0x94) [] (macb_poll) from [] (net_rx_action+0x6c/0x188) [] (net_rx_action) from [] (__do_softirq+0x108/0x280) [] (__do_softirq) from [] (irq_exit+0x84/0xf8) [] (irq_exit) from [] (handle_IRQ+0x68/0x8c) [] (handle_IRQ) from [] (gic_handle_irq+0x3c/0x60) [] (gic_handle_irq) from [] (__irq_svc+0x44/0x78) Exception stack(0xc056df20 to 0xc056df68) df20: 00000001 c0577430 00000000 c0577430 04ce8e0d 00000002 edfce238 00000000 df40: 04e20f78 00000002 c05981f4 00000000 00000008 c056df68 c0064008 c02d7658 df60: 20000013 ffffffff [] (__irq_svc) from [] (cpuidle_enter_state+0x54/0xf8) [] (cpuidle_enter_state) from [] (cpuidle_idle_call+0xe0/0x138) [] (cpuidle_idle_call) from [] (arch_cpu_idle+0x8/0x3c) [] (arch_cpu_idle) from [] (cpu_startup_entry+0xbc/0x124) [] (cpu_startup_entry) from [] (start_kernel+0x350/0x3b0) ---[ end trace d5fdc38641bd3a11 ]--- Mapped at: [] debug_dma_map_page+0x48/0x11c [] gem_rx_refill+0x154/0x1f8 [] macb_open+0x270/0x3e0 [] __dev_open+0x7c/0xfc [] __dev_change_flags+0x8c/0x140 Fixing this by passing the same size which is passed during mapping the memory to the unmap function as well. Signed-off-by: Soren Brinkmann Reviewed-by: Ben Hutchings Signed-off-by: David S. Miller --- drivers/net/ethernet/cadence/macb.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/net/ethernet/cadence/macb.c b/drivers/net/ethernet/cadence/macb.c index 1f03e2041e86..d0c38e01e99f 100644 --- a/drivers/net/ethernet/cadence/macb.c +++ b/drivers/net/ethernet/cadence/macb.c @@ -730,7 +730,7 @@ static int gem_rx(struct macb *bp, int budget) skb_put(skb, len); addr = MACB_BF(RX_WADDR, MACB_BFEXT(RX_WADDR, addr)); dma_unmap_single(&bp->pdev->dev, addr, - len, DMA_FROM_DEVICE); + bp->rx_buffer_size, DMA_FROM_DEVICE); skb->protocol = eth_type_trans(skb, bp->dev); skb_checksum_none_assert(skb); -- 2.39.2