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			89 lines
		
	
	
		
			2.6 KiB
		
	
	
	
		
			Diff
		
	
	
	
	
	
			
		
		
	
	
			89 lines
		
	
	
		
			2.6 KiB
		
	
	
	
		
			Diff
		
	
	
	
	
	
From: Felix Fietkau <nbd@nbd.name>
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Date: Sun, 12 Apr 2015 11:59:47 +0200
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Subject: [PATCH] bgmac: fix DMA rx corruption
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The driver needs to inform the hardware about the first invalid (not yet
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filled) rx slot, by writing its DMA descriptor pointer offset to the
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BGMAC_DMA_RX_INDEX register.
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This register was set to a value exceeding the rx ring size, effectively
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allowing the hardware constant access to the full ring, regardless of
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which slots are initialized.
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To fix this issue, always mark the last filled rx slot as invalid.
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Signed-off-by: Felix Fietkau <nbd@nbd.name>
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---
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--- a/drivers/net/ethernet/broadcom/bgmac.c
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+++ b/drivers/net/ethernet/broadcom/bgmac.c
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@@ -366,6 +366,16 @@ static int bgmac_dma_rx_skb_for_slot(str
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 	return 0;
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 }
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+static void bgmac_dma_rx_update_index(struct bgmac *bgmac,
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+				      struct bgmac_dma_ring *ring)
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+{
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+	wmb();
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+
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+	bgmac_write(bgmac, ring->mmio_base + BGMAC_DMA_RX_INDEX,
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+		    ring->index_base +
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+		    ring->end * sizeof(struct bgmac_dma_desc));
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+}
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+
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 static void bgmac_dma_rx_setup_desc(struct bgmac *bgmac,
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 				    struct bgmac_dma_ring *ring, int desc_idx)
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 {
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@@ -384,6 +394,8 @@ static void bgmac_dma_rx_setup_desc(stru
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 	dma_desc->addr_high = cpu_to_le32(upper_32_bits(ring->slots[desc_idx].dma_addr));
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 	dma_desc->ctl0 = cpu_to_le32(ctl0);
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 	dma_desc->ctl1 = cpu_to_le32(ctl1);
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+
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+	ring->end = desc_idx;
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 }
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 static void bgmac_dma_rx_poison_buf(struct device *dma_dev,
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@@ -411,9 +423,7 @@ static int bgmac_dma_rx_read(struct bgma
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 	end_slot &= BGMAC_DMA_RX_STATDPTR;
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 	end_slot /= sizeof(struct bgmac_dma_desc);
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-	ring->end = end_slot;
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-
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-	while (ring->start != ring->end) {
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+	while (ring->start != end_slot) {
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 		struct device *dma_dev = bgmac->core->dma_dev;
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 		struct bgmac_slot_info *slot = &ring->slots[ring->start];
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 		struct bgmac_rx_header *rx = slot->buf + BGMAC_RX_BUF_OFFSET;
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@@ -476,6 +486,8 @@ static int bgmac_dma_rx_read(struct bgma
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 			break;
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 	}
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+	bgmac_dma_rx_update_index(bgmac, ring);
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+
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 	return handled;
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 }
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@@ -695,6 +707,8 @@ static int bgmac_dma_init(struct bgmac *
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 		if (ring->unaligned)
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 			bgmac_dma_rx_enable(bgmac, ring);
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+		ring->start = 0;
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+		ring->end = 0;
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 		for (j = 0; j < ring->num_slots; j++) {
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 			err = bgmac_dma_rx_skb_for_slot(bgmac, &ring->slots[j]);
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 			if (err)
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@@ -703,12 +717,7 @@ static int bgmac_dma_init(struct bgmac *
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 			bgmac_dma_rx_setup_desc(bgmac, ring, j);
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 		}
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-		bgmac_write(bgmac, ring->mmio_base + BGMAC_DMA_RX_INDEX,
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-			    ring->index_base +
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-			    ring->num_slots * sizeof(struct bgmac_dma_desc));
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-
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-		ring->start = 0;
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-		ring->end = 0;
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+		bgmac_dma_rx_update_index(bgmac, ring);
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 	}
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 	return 0;
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