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* [PATCH] net: macb: Align the dma and coherent dma masks
@ 2022-02-09  9:43 Harini Katakam
  2022-02-09 10:24 ` Nicolas Ferre
                   ` (2 more replies)
  0 siblings, 3 replies; 4+ messages in thread
From: Harini Katakam @ 2022-02-09  9:43 UTC (permalink / raw)
  To: nicolas.ferre, davem, claudiu.beznea, andrei.pistirica, kuba,
	Conor.Dooley
  Cc: netdev, linux-kernel, michal.simek, harinikatakamlinux,
	harini.katakam, mstamand

From: Marc St-Amand <mstamand@ciena.com>

Single page and coherent memory blocks can use different DMA masks
when the macb accesses physical memory directly. The kernel is clever
enough to allocate pages that fit into the requested address width.

When using the ARM SMMU, the DMA mask must be the same for single
pages and big coherent memory blocks. Otherwise the translation
tables turn into one big mess.

  [   74.959909] macb ff0e0000.ethernet eth0: DMA bus error: HRESP not OK
  [   74.959989] arm-smmu fd800000.smmu: Unhandled context fault: fsr=0x402, iova=0x3165687460, fsynr=0x20001, cbfrsynra=0x877, cb=1
  [   75.173939] macb ff0e0000.ethernet eth0: DMA bus error: HRESP not OK
  [   75.173955] arm-smmu fd800000.smmu: Unhandled context fault: fsr=0x402, iova=0x3165687460, fsynr=0x20001, cbfrsynra=0x877, cb=1

Since using the same DMA mask does not hurt direct 1:1 physical
memory mappings, this commit always aligns DMA and coherent masks.

Signed-off-by: Marc St-Amand <mstamand@ciena.com>
Signed-off-by: Harini Katakam <harini.katakam@xilinx.com>
---
 drivers/net/ethernet/cadence/macb_main.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/cadence/macb_main.c b/drivers/net/ethernet/cadence/macb_main.c
index 1ce20bf52f72..4c231159b562 100644
--- a/drivers/net/ethernet/cadence/macb_main.c
+++ b/drivers/net/ethernet/cadence/macb_main.c
@@ -4765,7 +4765,7 @@ static int macb_probe(struct platform_device *pdev)
 
 #ifdef CONFIG_ARCH_DMA_ADDR_T_64BIT
 	if (GEM_BFEXT(DAW64, gem_readl(bp, DCFG6))) {
-		dma_set_mask(&pdev->dev, DMA_BIT_MASK(44));
+		dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(44));
 		bp->hw_dma_cap |= HW_DMA_CAP_64B;
 	}
 #endif
-- 
2.17.1


^ permalink raw reply related	[flat|nested] 4+ messages in thread

end of thread, other threads:[~2022-02-10 15:10 UTC | newest]

Thread overview: 4+ messages (download: mbox.gz follow: Atom feed
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2022-02-09  9:43 [PATCH] net: macb: Align the dma and coherent dma masks Harini Katakam
2022-02-09 10:24 ` Nicolas Ferre
2022-02-09 11:15 ` conor.dooley
2022-02-10 15:10 ` patchwork-bot+netdevbpf

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