Subject: [PATCH 2/2] sh_eth: fix WARNING in dma_free_coherent()

From: Sergei Shtylyov <[email-masked]>
Date: Fri, 30 Oct 2015 00:52:45 +0300

Iff the first dma_alloc_coherent()  call fails in sh_eth_ring_init(), the
following  is printed to the kernel console:

WARNING: CPU: 0 PID: 1 at drivers/base/dma-mapping.c:334 dma_common_free_remap+0x48/0x6c()
trying to free invalid coherent area:   (null)
Modules linked in:
CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.3.0-rc7-dirty #969
Hardware name: Generic R8A7791 (Flattened Device Tree)
Backtrace:
[<c0013820>] (dump_backtrace) from [<c00139bc>] (show_stack+0x18/0x1c)
 r6:c0662856 r5:00000009 r4:00000000 r3:00204140
[<c00139a4>] (show_stack) from [<c0227510>] (dump_stack+0x74/0x90)
[<c022749c>] (dump_stack) from [<c0026ef4>] (warn_slowpath_common+0x8c/0xb8)
 r4:ee84dce0 r3:c0712774
[<c0026e68>] (warn_slowpath_common) from [<c0026fc4>] (warn_slowpath_fmt+0x38/0x40)
 r8:ee7f8000 r7:c0734520 r6:00001000 r5:20000008 r4:00000000
[<c0026f90>] (warn_slowpath_fmt) from [<c02df404>] (dma_common_free_remap+0x48/0x6c)
 r3:00000000 r2:c0662871
[<c02df3bc>] (dma_common_free_remap) from [<c001b9fc>] (__arm_dma_free+0xb8/0xd4)
r6:00000001 r5:00000000 r4:00001000 r3:ee8c5584
[<c001b944>] (__arm_dma_free) from [<c001ba68>] (arm_dma_free+0x24/0x2c)
 r10:0000016b r8:00000000 r7:ee9bc830 r6:00000000 r5:00000400 r4:ee9bc800
[<c001ba44>] (arm_dma_free) from [<c032ebf0>] (sh_eth_ring_init+0x110/0x138)
[<c032eae0>] (sh_eth_ring_init) from [<c033179c>] (sh_eth_open+0x94/0x1f4)
 r6:00000000 r5:ee9bcd18 r4:ee9bc800
[<c0331708>] (sh_eth_open) from [<c041bf7c>] (__dev_open+0x84/0x104)
 r6:c0565c50 r5:00000000 r4:ee9bc800
[<c041bef8>] (__dev_open) from [<c041c208>] (__dev_change_flags+0x94/0x13c)
 r7:00001002 r6:00000001 r5:00001003 r4:ee9bc800
[<c041c174>] (__dev_change_flags) from [<c041c2e8>] (dev_change_flags+0x20/0x50)
 r7:c072c8a0 r6:00000138 r5:00001002 r4:ee9bc800
[<c041c2c8>] (dev_change_flags) from [<c06e8d4c>] (ip_auto_config+0x174/0xf7c)
 r8:00001002 r7:c072c8a0 r6:c0700040 r5:00000001 r4:ee9bc800 r3:00000101
[<c06e8bd8>] (ip_auto_config) from [<c000a810>] (do_one_initcall+0x100/0x1c8)
 r10:c06f883c r9:00000000 r8:c06e8bd8 r7:c0734000 r6:c070e918 r5:c070e918
 r4:ee083640
[<c000a710>] (do_one_initcall) from [<c06c9ddc>] (kernel_init_freeable+0x11c/0x1ec)
 r10:c06f883c r9:00000000 r8:00000099 r7:c0734000 r6:c070372c r5:c06f8834
 r4:00000007
[<c06c9cc0>] (kernel_init_freeable) from [<c0514d78>] (kernel_init+0x14/0xec)
 r10:00000000 r8:00000000 r7:00000000 r6:00000000 r5:c0514d64 r4:c0734000
[<c0514d64>] (kernel_init) from [<c0010458>] (ret_from_fork+0x14/0x3c)
 r4:00000000 r3:ee84c000

This is because the code jumps to a wrong label and so tries to free yet
unallocated coherent memory.  Fix the *goto* in question.

Signed-off-by: Sergei Shtylyov <[email-masked]>

---
 drivers/net/ethernet/renesas/sh_eth.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Index: net/drivers/net/ethernet/renesas/sh_eth.c
===================================================================
--- net.orig/drivers/net/ethernet/renesas/sh_eth.c
+++ net/drivers/net/ethernet/renesas/sh_eth.c
@@ -1232,7 +1232,7 @@ static int sh_eth_ring_init(struct net_d
 					  GFP_KERNEL);
 	if (!mdp->rx_ring) {
 		ret = -ENOMEM;
-		goto desc_ring_free;
+		goto skb_ring_free;
 	}
 
 	mdp->dirty_rx = 0;