From 964ea7c1cea6228aa414f4aee5acf25bcd87ca21 Mon Sep 17 00:00:00 2001 From: Ian Campbell Date: Thu, 8 May 2014 22:26:33 +0100 Subject: [PATCH] net/designware: ensure cache invalidations are aligned to ARCH_DMA_MINALIGN This is required at least on ARM. When sending instead of simply invalidating the entire descriptor, flush as little as possible while still respecting ARCH_DMA_MINALIGN, as requested by Alexey. Signed-off-by: Ian Campbell Cc: Alexey Brodkin --- drivers/net/designware.c | 18 +++++++++++++----- 1 file changed, 13 insertions(+), 5 deletions(-) diff --git a/drivers/net/designware.c b/drivers/net/designware.c index 41ab3ac0b6..fa816bf2f6 100644 --- a/drivers/net/designware.c +++ b/drivers/net/designware.c @@ -280,10 +280,18 @@ static int dw_eth_send(struct eth_device *dev, void *packet, int length) u32 desc_num = priv->tx_currdescnum; struct dmamacdescr *desc_p = &priv->tx_mac_descrtable[desc_num]; - /* Invalidate only "status" field for the following check */ - invalidate_dcache_range((unsigned long)&desc_p->txrx_status, - (unsigned long)&desc_p->txrx_status + - sizeof(desc_p->txrx_status)); + /* + * Strictly we only need to invalidate the "txrx_status" field + * for the following check, but on some platforms we cannot + * invalidate only 4 bytes, so roundup to + * ARCH_DMA_MINALIGN. This is safe because the individual + * descriptors in the array are each aligned to + * ARCH_DMA_MINALIGN. + */ + invalidate_dcache_range( + (unsigned long)desc_p, + (unsigned long)desc_p + + roundup(sizeof(desc_p->txrx_status), ARCH_DMA_MINALIGN)); /* Check if the descriptor is owned by CPU */ if (desc_p->txrx_status & DESC_TXSTS_OWNBYDMA) { @@ -351,7 +359,7 @@ static int dw_eth_recv(struct eth_device *dev) /* Invalidate received data */ invalidate_dcache_range((unsigned long)desc_p->dmamac_addr, (unsigned long)desc_p->dmamac_addr + - length); + roundup(length, ARCH_DMA_MINALIGN)); NetReceive(desc_p->dmamac_addr, length); -- 2.25.1