Patchwork [v2,4/5] net: ep93xx_eth: drop GFP_DMA from call to dma_alloc_coherent()

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Submitter Mika Westerberg
Date June 2, 2011, 6:59 p.m.
Message ID <c2142b13f03e2d183a4f28b9b2b8fc81b30530a8.1307040443.git.mika.westerberg@iki.fi>
Download mbox | patch
Permalink /patch/98459/
State Changes Requested
Delegated to: David Miller
Headers show

Comments

Mika Westerberg - June 2, 2011, 6:59 p.m.
Commit a197b59ae6e8 (mm: fail GFP_DMA allocations when ZONE_DMA is not
configured) made page allocator to return NULL if GFP_DMA is set but
CONFIG_ZONE_DMA is disabled.

This causes ep93xx_eth to fail:

 WARNING: at mm/page_alloc.c:2251 __alloc_pages_nodemask+0x11c/0x638()
 Modules linked in:
 [<c0035498>] (unwind_backtrace+0x0/0xf4) from [<c0043da4>] (warn_slowpath_common+0x48/0x60)
 [<c0043da4>] (warn_slowpath_common+0x48/0x60) from [<c0043dd8>] (warn_slowpath_null+0x1c/0x24)
 [<c0043dd8>] (warn_slowpath_null+0x1c/0x24) from [<c0083b6c>] (__alloc_pages_nodemask+0x11c/0x638)
 [<c0083b6c>] (__alloc_pages_nodemask+0x11c/0x638) from [<c00366fc>] (__dma_alloc+0x8c/0x3ec)
 [<c00366fc>] (__dma_alloc+0x8c/0x3ec) from [<c0036adc>] (dma_alloc_coherent+0x54/0x60)
 [<c0036adc>] (dma_alloc_coherent+0x54/0x60) from [<c0227808>] (ep93xx_open+0x20/0x864)
 [<c0227808>] (ep93xx_open+0x20/0x864) from [<c0283144>] (__dev_open+0xb8/0x108)
 [<c0283144>] (__dev_open+0xb8/0x108) from [<c0280528>] (__dev_change_flags+0x70/0x128)
 [<c0280528>] (__dev_change_flags+0x70/0x128) from [<c0283054>] (dev_change_flags+0x10/0x48)
 [<c0283054>] (dev_change_flags+0x10/0x48) from [<c001a720>] (ip_auto_config+0x190/0xf68)
 [<c001a720>] (ip_auto_config+0x190/0xf68) from [<c00233b0>] (do_one_initcall+0x34/0x18c)
 [<c00233b0>] (do_one_initcall+0x34/0x18c) from [<c0008400>] (kernel_init+0x94/0x134)
 [<c0008400>] (kernel_init+0x94/0x134) from [<c0030858>] (kernel_thread_exit+0x0/0x8)

Since there is no restrictions for DMA on ep93xx, we can fix this by just
removing the GFP_DMA flag from the call.

Signed-off-by: Mika Westerberg <mika.westerberg@iki.fi>
Acked-by: Russell King <rmk+kernel@arm.linux.org.uk>
---
 drivers/net/arm/ep93xx_eth.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
hartleys - June 9, 2011, 8:59 p.m.
On Thursday, June 02, 2011 12:00 PM, Mika Westerberg wrote:
>
> Commit a197b59ae6e8 (mm: fail GFP_DMA allocations when ZONE_DMA is not
> configured) made page allocator to return NULL if GFP_DMA is set but
> CONFIG_ZONE_DMA is disabled.
>
> This causes ep93xx_eth to fail:
>
>  WARNING: at mm/page_alloc.c:2251 __alloc_pages_nodemask+0x11c/0x638()
>  Modules linked in:
>  [<c0035498>] (unwind_backtrace+0x0/0xf4) from [<c0043da4>] (warn_slowpath_common+0x48/0x60)
>  [<c0043da4>] (warn_slowpath_common+0x48/0x60) from [<c0043dd8>] (warn_slowpath_null+0x1c/0x24)
>  [<c0043dd8>] (warn_slowpath_null+0x1c/0x24) from [<c0083b6c>] (__alloc_pages_nodemask+0x11c/0x638)
>  [<c0083b6c>] (__alloc_pages_nodemask+0x11c/0x638) from [<c00366fc>] (__dma_alloc+0x8c/0x3ec)
>  [<c00366fc>] (__dma_alloc+0x8c/0x3ec) from [<c0036adc>] (dma_alloc_coherent+0x54/0x60)
>  [<c0036adc>] (dma_alloc_coherent+0x54/0x60) from [<c0227808>] (ep93xx_open+0x20/0x864)
>  [<c0227808>] (ep93xx_open+0x20/0x864) from [<c0283144>] (__dev_open+0xb8/0x108)
>  [<c0283144>] (__dev_open+0xb8/0x108) from [<c0280528>] (__dev_change_flags+0x70/0x128)
>  [<c0280528>] (__dev_change_flags+0x70/0x128) from [<c0283054>] (dev_change_flags+0x10/0x48)
>  [<c0283054>] (dev_change_flags+0x10/0x48) from [<c001a720>] (ip_auto_config+0x190/0xf68)
>  [<c001a720>] (ip_auto_config+0x190/0xf68) from [<c00233b0>] (do_one_initcall+0x34/0x18c)
>  [<c00233b0>] (do_one_initcall+0x34/0x18c) from [<c0008400>] (kernel_init+0x94/0x134)
>  [<c0008400>] (kernel_init+0x94/0x134) from [<c0030858>] (kernel_thread_exit+0x0/0x8)
>
> Since there is no restrictions for DMA on ep93xx, we can fix this by just
> removing the GFP_DMA flag from the call.
> 
> Signed-off-by: Mika Westerberg <mika.westerberg@iki.fi>
> Acked-by: Russell King <rmk+kernel@arm.linux.org.uk>

If this is a bug fix maybe it should be submitted as a separate patch.  Russell could
apply it now to fix the problem.

Regardless,

Acked-by: H Hartley Sweeten <hsweeten@visionengravers.com>
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Patch

diff --git a/drivers/net/arm/ep93xx_eth.c b/drivers/net/arm/ep93xx_eth.c
index 0c9df11..56b51a1 100644
--- a/drivers/net/arm/ep93xx_eth.c
+++ b/drivers/net/arm/ep93xx_eth.c
@@ -495,7 +495,7 @@  static int ep93xx_alloc_buffers(struct ep93xx_priv *ep)
 	int i;
 
 	ep->descs = dma_alloc_coherent(dev, sizeof(struct ep93xx_descs),
-				&ep->descs_dma_addr, GFP_KERNEL | GFP_DMA);
+				&ep->descs_dma_addr, GFP_KERNEL);
 	if (ep->descs == NULL)
 		return 1;