https://github.com/torvalds/linux
Revision f1c089e3192f1afdfa76226dc38ef81b08ac810d authored by Mika Westerberg on 11 June 2011, 08:39:58 UTC, committed by David S. Miller on 11 June 2011, 23:25:16 UTC
Russell King said: > > So, to summarize what its doing: > > 1. It allocates buffers for rx and tx. > 2. It maps them with dma_map_single(). > This transfers ownership of the buffer to the DMA device. > 3. In ep93xx_xmit, > 3a. It copies the data into the buffer with skb_copy_and_csum_dev() > This violates the DMA buffer ownership rules - the CPU should > not be writing to this buffer while it is (in principle) owned > by the DMA device. > 3b. It then calls dma_sync_single_for_cpu() for the buffer. > This transfers ownership of the buffer to the CPU, which surely > is the wrong direction. > 4. In ep93xx_rx, > 4a. It calls dma_sync_single_for_cpu() for the buffer. > This at least transfers the DMA buffer ownership to the CPU > before the CPU reads the buffer > 4b. It then uses skb_copy_to_linear_data() to copy the data out. > At no point does it transfer ownership back to the DMA device. > 5. When the driver is removed, it dma_unmap_single()'s the buffer. > This transfers ownership of the buffer to the CPU. > 6. It frees the buffer. > > While it may work on ep93xx, it's not respecting the DMA API rules, > and with DMA debugging enabled it will probably encounter quite a few > warnings. This patch fixes these violations. Signed-off-by: Mika Westerberg <mika.westerberg@iki.fi> Acked-by: Russell King <rmk+kernel@arm.linux.org.uk> Acked-by: H Hartley Sweeten <hsweeten@visionengravers.com> Tested-by: Petr Stetiar <ynezz@true.cz> Signed-off-by: David S. Miller <davem@davemloft.net>
1 parent 1f758a4
Tip revision: f1c089e3192f1afdfa76226dc38ef81b08ac810d authored by Mika Westerberg on 11 June 2011, 08:39:58 UTC
net: ep93xx_eth: fix DMA API violations
net: ep93xx_eth: fix DMA API violations
Tip revision: f1c089e
File | Mode | Size |
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Kbuild | -rw-r--r-- | 61 bytes |
atmel_lcdc.h | -rw-r--r-- | 7.1 KB |
aty128.h | -rw-r--r-- | 13.2 KB |
broadsheetfb.h | -rw-r--r-- | 2.1 KB |
cirrus.h | -rw-r--r-- | 5.7 KB |
cvisionppc.h | -rw-r--r-- | 1.5 KB |
da8xx-fb.h | -rw-r--r-- | 2.2 KB |
edid.h | -rw-r--r-- | 284 bytes |
epson1355.h | -rw-r--r-- | 2.4 KB |
gbe.h | -rw-r--r-- | 10.5 KB |
hecubafb.h | -rw-r--r-- | 1.5 KB |
iga.h | -rw-r--r-- | 787 bytes |
ili9320.h | -rw-r--r-- | 5.8 KB |
kyro.h | -rw-r--r-- | 2.4 KB |
mach64.h | -rw-r--r-- | 47.1 KB |
maxinefb.h | -rw-r--r-- | 1.2 KB |
mbxfb.h | -rw-r--r-- | 2.1 KB |
metronomefb.h | -rw-r--r-- | 1.5 KB |
mipi_display.h | -rw-r--r-- | 4.1 KB |
neomagic.h | -rw-r--r-- | 4.9 KB |
newport.h | -rw-r--r-- | 18.6 KB |
omap-panel-generic-dpi.h | -rw-r--r-- | 1.2 KB |
omap-panel-nokia-dsi.h | -rw-r--r-- | 886 bytes |
omapdss.h | -rw-r--r-- | 17.8 KB |
permedia2.h | -rw-r--r-- | 9.0 KB |
platform_lcd.h | -rw-r--r-- | 550 bytes |
pm3fb.h | -rw-r--r-- | 45.3 KB |
pmag-ba-fb.h | -rw-r--r-- | 1.0 KB |
pmagb-b-fb.h | -rw-r--r-- | 2.3 KB |
pxa168fb.h | -rw-r--r-- | 2.7 KB |
radeon.h | -rw-r--r-- | 109.2 KB |
s1d13xxxfb.h | -rw-r--r-- | 9.9 KB |
sgivw.h | -rw-r--r-- | 24.1 KB |
sh_mipi_dsi.h | -rw-r--r-- | 859 bytes |
sh_mobile_hdmi.h | -rw-r--r-- | 972 bytes |
sh_mobile_lcdc.h | -rw-r--r-- | 2.8 KB |
sh_mobile_meram.h | -rw-r--r-- | 1.7 KB |
sisfb.h | -rw-r--r-- | 7.7 KB |
sstfb.h | -rw-r--r-- | 11.0 KB |
tdfx.h | -rw-r--r-- | 5.3 KB |
tgafb.h | -rw-r--r-- | 6.9 KB |
trident.h | -rw-r--r-- | 3.2 KB |
udlfb.h | -rw-r--r-- | 2.7 KB |
uvesafb.h | -rw-r--r-- | 3.7 KB |
vga.h | -rw-r--r-- | 14.2 KB |
w100fb.h | -rw-r--r-- | 3.7 KB |
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