Patchwork pch_gbe: set dma mask to only 32 bit

login
register
mail settings
Submitter Veaceslav Falico
Date Feb. 7, 2012, 7:23 p.m.
Message ID <20120207192354.GA7770@darkmag.usersys.redhat.com>
Download mbox | patch
Permalink /patch/139997/
State Changes Requested
Delegated to: David Miller
Headers show

Comments

Veaceslav Falico - Feb. 7, 2012, 7:23 p.m.
Because pch_gbe_rx_desc->buffer_addr is u32, we cannot set dma mask to 64
bit or otherwise we could end up loosing the higher 32 bit from the return
of dma_map_single(). Removing DMA_BIT_MASK(64) setting will solve it.

Signed-off-by: Veaceslav Falico <vfalico@redhat.com>
---
--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
David Miller - Feb. 9, 2012, 1:06 a.m.
From: Veaceslav Falico <vfalico@redhat.com>
Date: Tue, 7 Feb 2012 20:23:54 +0100

> Because pch_gbe_rx_desc->buffer_addr is u32, we cannot set dma mask to 64
> bit or otherwise we could end up loosing the higher 32 bit from the return
> of dma_map_single(). Removing DMA_BIT_MASK(64) setting will solve it.
> 
> Signed-off-by: Veaceslav Falico <vfalico@redhat.com>

The logic here makes no sense.

> -	if (pci_set_dma_mask(pdev, DMA_BIT_MASK(64))
> -		|| pci_set_consistent_dma_mask(pdev, DMA_BIT_MASK(64))) {
> -		ret = pci_set_dma_mask(pdev, DMA_BIT_MASK(32));
> +	if (pci_set_dma_mask(pdev, DMA_BIT_MASK(32))) {
> +		ret = pci_set_consistent_dma_mask(pdev,
> +						  DMA_BIT_MASK(32));

You want to take this branch on success, not failure.  pci_set_dma_mask()
returns 0 on success.

Something like:

	ret = pci_set_dma_mask(pdev, DMA_BIT_MASK(32));
	if (ret ||
	    (ret = pci_set_consistent_dma_mask(pdev, DMA_BIT_MASK(32)))) {
		dev_err(&pdev->dev, "ERR: No usable DMA "
			"configuration, aborting\n");
		goto err_disable_device;
	}
--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Patch

diff --git a/drivers/net/ethernet/oki-semi/pch_gbe/pch_gbe_main.c b/drivers/net/ethernet/oki-semi/pch_gbe/pch_gbe_main.c
index 3ead111..6c6713b 100644
--- a/drivers/net/ethernet/oki-semi/pch_gbe/pch_gbe_main.c
+++ b/drivers/net/ethernet/oki-semi/pch_gbe/pch_gbe_main.c
@@ -2397,17 +2397,13 @@  static int pch_gbe_probe(struct pci_dev *pdev,
 	if (ret)
 		return ret;
 
-	if (pci_set_dma_mask(pdev, DMA_BIT_MASK(64))
-		|| pci_set_consistent_dma_mask(pdev, DMA_BIT_MASK(64))) {
-		ret = pci_set_dma_mask(pdev, DMA_BIT_MASK(32));
+	if (pci_set_dma_mask(pdev, DMA_BIT_MASK(32))) {
+		ret = pci_set_consistent_dma_mask(pdev,
+						  DMA_BIT_MASK(32));
 		if (ret) {
-			ret = pci_set_consistent_dma_mask(pdev,
-							  DMA_BIT_MASK(32));
-			if (ret) {
-				dev_err(&pdev->dev, "ERR: No usable DMA "
-					"configuration, aborting\n");
-				goto err_disable_device;
-			}
+			dev_err(&pdev->dev, "ERR: No usable DMA "
+				"configuration, aborting\n");
+			goto err_disable_device;
 		}
 	}