Re: [PATCH 1/4] usb: dwc3: dwc3-omap: set dma_mask for dwc3 inorderfor host mode to work

From: Felipe Balbi
Date: Tue Mar 05 2013 - 10:11:36 EST


On Tue, Mar 05, 2013 at 08:29:34PM +0530, kishon wrote:
> Hi,
>
> On Tuesday 05 March 2013 08:24 PM, Felipe Balbi wrote:
> >On Tue, Mar 05, 2013 at 07:51:57PM +0530, Kishon Vijay Abraham I wrote:
> >>While creating the child devices, *of_platform_populate* sets only
> >>coherent_dma_mask but USBHCD sets *uses_dma* (determines whether the
> >>controller is DMA'able) based on dma_mask. So If we haven't explicitly set
> >>dma_mask, the HCD thinks the controller is not DMA'able and the
> >>controller will fail. So explicity set dma_mask for dwc3 after
> >>*of_platform_populate*.
> >>
> >>Signed-off-by: Kishon Vijay Abraham I <kishon@xxxxxx>
> >>---
> >> drivers/usb/dwc3/dwc3-omap.c | 10 ++++++++++
> >> 1 file changed, 10 insertions(+)
> >>
> >>diff --git a/drivers/usb/dwc3/dwc3-omap.c b/drivers/usb/dwc3/dwc3-omap.c
> >>index 35b9673..19c6e72 100644
> >>--- a/drivers/usb/dwc3/dwc3-omap.c
> >>+++ b/drivers/usb/dwc3/dwc3-omap.c
> >>@@ -277,6 +277,14 @@ static void dwc3_omap_disable_irqs(struct dwc3_omap *omap)
> >> dwc3_omap_writel(omap->base, USBOTGSS_IRQENABLE_SET_0, 0x00);
> >> }
> >>
> >>+static u64 dwc3_omap_dma_mask = DMA_BIT_MASK(32);
> >>+
> >>+static int dwc3_omap_set_dmamask(struct device *dev, void *c)
> >>+{
> >>+ dev->dma_mask = &dwc3_omap_dma_mask;
> >>+ return 0;
> >>+}
> >>+
> >> static int dwc3_omap_probe(struct platform_device *pdev)
> >> {
> >> struct device_node *node = pdev->dev.of_node;
> >>@@ -381,6 +389,8 @@ static int dwc3_omap_probe(struct platform_device *pdev)
> >> return ret;
> >> }
> >>
> >>+ device_for_each_child(&pdev->dev, NULL, dwc3_omap_set_dmamask);
> >
> >I don't think this is correct. Child should be setting its own by
> >copying from parent. In summary I think we should add this to dwc3 core:
> >
> >dma_set_coherent_mask(&pdev->dev, pdev->dev.parent->coherent_dma_mask);
> >pdev->dev.dma_mask = pdev->dev.parent->dma_mask;
> >pdev->dev.dma_parms = pdev->dev.parent->dma_parms;
> >
> >And add the same thing to xhci-plat.c btw.
>
> hmm.. ok.

another thing, this means that we can remove similar code from
dwc3-pci.c and dwc3-exynos.c ;-)

--
balbi

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