[PATCH net-next] enic: set DMA mask to 47 bit

[PATCH net-next] enic: set DMA mask to 47 bit

[Govindarajulu Varadarajan]

In commit 624dbf55a359b ("driver/net: enic: Try DMA 64 first, then
failover to DMA") DMA mask was changed from 40 bits to 64 bits.
Hardware actually supports only 47 bits.

Fixes: 624dbf55a359b("driver/net: enic: Try DMA 64 first, then failover
to DMA")
Signed-off-by: Govindarajulu Varadarajan <gvaradar@cisco.com>
---
 drivers/net/ethernet/cisco/enic/enic_main.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/net/ethernet/cisco/enic/enic_main.c b/drivers/net/ethernet/cisco/enic/enic_main.c
index 81684acf52af..8a8b12b720ef 100644
--- a/drivers/net/ethernet/cisco/enic/enic_main.c
+++ b/drivers/net/ethernet/cisco/enic/enic_main.c
@@ -2747,11 +2747,11 @@ static int enic_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
 	pci_set_master(pdev);
 
 	/* Query PCI controller on system for DMA addressing
-	 * limitation for the device.  Try 64-bit first, and
+	 * limitation for the device.  Try 47-bit first, and
 	 * fail to 32-bit.
 	 */
 
-	err = pci_set_dma_mask(pdev, DMA_BIT_MASK(64));
+	err = pci_set_dma_mask(pdev, DMA_BIT_MASK(47));
 	if (err) {
 		err = pci_set_dma_mask(pdev, DMA_BIT_MASK(32));
 		if (err) {
@@ -2765,10 +2765,10 @@ static int enic_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
 			goto err_out_release_regions;
 		}
 	} else {
-		err = pci_set_consistent_dma_mask(pdev, DMA_BIT_MASK(64));
+		err = pci_set_consistent_dma_mask(pdev, DMA_BIT_MASK(47));
 		if (err) {
 			dev_err(dev, "Unable to obtain %u-bit DMA "
-				"for consistent allocations, aborting\n", 64);
+				"for consistent allocations, aborting\n", 47);
 			goto err_out_release_regions;
 		}
 		using_dac = 1;
-- 
2.17.0

Re: [PATCH net-next] enic: set DMA mask to 47 bit

[David Miller]

From: Govindarajulu Varadarajan <gvaradar@cisco.com>
Date: Tue, 22 May 2018 06:37:24 -0700

> In commit 624dbf55a359b ("driver/net: enic: Try DMA 64 first, then
> failover to DMA") DMA mask was changed from 40 bits to 64 bits.
> Hardware actually supports only 47 bits.
> 
> Fixes: 624dbf55a359b("driver/net: enic: Try DMA 64 first, then failover
> to DMA")

Do not chop up long Fixes: tag lines, they should always be one
single line.

Also, need a space after the SHA1 ID.

> Signed-off-by: Govindarajulu Varadarajan <gvaradar@cisco.com>

This is a fix for a bug which is very old, back to 3.12  Therefore
you should target the 'net' tree, rather than 'net-next'.