[U-Boot] [PATCH 3/2] net/designware: reorder struct dw_eth_dev to pack more efficiently.

Ian Campbell ijc at hellion.org.uk
Thu May 1 21:01:58 CEST 2014


The {tx,rx}_mac_descrtable fields are aligned to ARCH_DMA_MINALIGN, which could
be 256 or even larger. That means there is a potentially huge hole in the
struct before those fields, so move them to the front where they are better
packed.

Moving them to the front also helps ensure that so long as dw_eth_dev is
properly aligned (which it is since "net/designware: ensure device private data
is DMA aligned.") the {tx,rx}_mac_descrtable will be too, or at least avoids
having to worry too much about compiler specifics.

Signed-off-by: Ian Campbell <ijc at hellion.org.uk>
Cc: Alexey Brodkin <abrodkin at synopsys.com>
---
 drivers/net/designware.h | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/net/designware.h b/drivers/net/designware.h
index 382b0c7..6d94b3a 100644
--- a/drivers/net/designware.h
+++ b/drivers/net/designware.h
@@ -215,13 +215,13 @@ struct dmamacdescr {
 #endif
 
 struct dw_eth_dev {
+	struct dmamacdescr tx_mac_descrtable[CONFIG_TX_DESCR_NUM];
+	struct dmamacdescr rx_mac_descrtable[CONFIG_RX_DESCR_NUM];
+
 	u32 interface;
 	u32 tx_currdescnum;
 	u32 rx_currdescnum;
 
-	struct dmamacdescr tx_mac_descrtable[CONFIG_TX_DESCR_NUM];
-	struct dmamacdescr rx_mac_descrtable[CONFIG_RX_DESCR_NUM];
-
 	char txbuffs[TX_TOTAL_BUFSIZE];
 	char rxbuffs[RX_TOTAL_BUFSIZE];
 
-- 
1.9.0





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