On 06/03/2013 08:51 PM, Greg KH wrote: > On Thu, May 23, 2013 at 05:46:44PM +0300, Roger Quadros wrote: >> On 05/23/2013 05:11 PM, Alan Stern wrote: >>> On Thu, 23 May 2013, Roger Quadros wrote: >>> >>>> Device tree probed devices don't get dma_mask set. Previously >>>> we were setting the dma_mask pointer only if it was NULL. >>>> However, the address of 'omap_ehci_dma_mask' would change >>>> each time the module is unloaded and loaded back thus causing >>>> the devices dma_mask pointer to be invalid on the next load. >>>> >>>> This will cause page faults if any driver tries to access the >>>> old dma_mask pointer. >>>> >>>> Unconditionally re-setting the dma_mask pointer fixes this problem. >>> >>>> diff --git a/drivers/usb/host/ehci-omap.c b/drivers/usb/host/ehci-omap.c >>>> index 3d1491b..b33e306 100644 >>>> --- a/drivers/usb/host/ehci-omap.c >>>> +++ b/drivers/usb/host/ehci-omap.c >>>> @@ -146,8 +146,7 @@ static int ehci_hcd_omap_probe(struct platform_device *pdev) >>>> * Since shared usb code relies on it, set it here for now. >>>> * Once we have dma capability bindings this can go away. >>>> */ >>>> - if (!pdev->dev.dma_mask) >>>> - pdev->dev.dma_mask = &omap_ehci_dma_mask; >>>> + pdev->dev.dma_mask = &omap_ehci_dma_mask; >>> >>> Is this the solution that people have agreed on? There has been a lot >>> of discussion on this topic. In particular, there has been talk about >>> fixing it in the DT core. >> >> Fixing it in DT core would be best. > > Then please do that. > It seems [1] went into 3.10-rc3 so this issue is fixed for 3.10. [1] https://patchwork.kernel.org/patch/2537021/ cheers, -roger -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
