Re: [PATCH 1/2] ufs-pltfrm: initialize DMA mask for device-tree probed device

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 




On 8/19/2013 8:02 PM, James Bottomley wrote:
On Mon, 2013-08-19 at 22:56 +0900, Akinobu Mita wrote:
The device-tree probed device for ARM doesn't have dev->dma_mask.
So dma_set_mask() for the device doesn't succeed.  The popular trick
for this is - dev->dma_mask = &dev->coherent_dma_mask;

Currently there is no dma_set_mask() call in ufs-pltfrm, but the
forthcoming fix needs proper DMA mask setting in ufs core driver.  So
initializing dev->dma_mask as described above is required.

Signed-off-by: Akinobu Mita <mita@xxxxxxxxxxxx>
Cc: Sujit Reddy Thumma <sthumma@xxxxxxxxxxxxxx>
Cc: Vinayak Holikatti <vinholikatti@xxxxxxxxx>
Cc: Santosh Y <santoshsy@xxxxxxxxx>
Cc: "James E.J. Bottomley" <JBottomley@xxxxxxxxxxxxx>
Cc: linux-scsi@xxxxxxxxxxxxxxx
---
  drivers/scsi/ufs/ufshcd-pltfrm.c | 3 +++
  1 file changed, 3 insertions(+)

diff --git a/drivers/scsi/ufs/ufshcd-pltfrm.c b/drivers/scsi/ufs/ufshcd-pltfrm.c
index 94ba40c..c780840 100644
--- a/drivers/scsi/ufs/ufshcd-pltfrm.c
+++ b/drivers/scsi/ufs/ufshcd-pltfrm.c
@@ -122,6 +122,9 @@ static int ufshcd_pltfrm_probe(struct platform_device *pdev)
  		goto out;
  	}

+	if (!dev->dma_mask)
+		dev->dma_mask = &dev->coherent_dma_mask;
+

If the DMA mask is NULL, it means there's buggy platform code somewhere;
I'm not sure we should be hacking a fix in a SCSI driver.

Yes, ideally DT core should do this, there are patches lying around but
are not converged. Adding devicetree@xxxxxxxxxxxxxxx to see if someone
has better suggestions.

Recent additions to kernel with similar hacks -
https://patchwork.kernel.org/patch/2537021/


--
Regards,
Sujit
--
To unsubscribe from this list: send the line "unsubscribe devicetree" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html




[Index of Archives]     [Device Tree Compilter]     [Device Tree Spec]     [Linux Driver Backports]     [Video for Linux]     [Linux USB Devel]     [Linux PCI Devel]     [Linux Audio Users]     [Linux Kernel]     [Linux SCSI]     [XFree86]     [Yosemite Backpacking]
  Powered by Linux