On Fri, Apr 15, 2016 at 02:56:17PM +0300, Grygorii Strashko wrote:
> From c68225e97e8c9505aca4ceab19a0d8e4dde31b73 Mon Sep 17 00:00:00 2001
> From: Grygorii Strashko <grygorii.strashko@xxxxxx>
> Date: Thu, 31 Mar 2016 19:40:52 +0300
> Subject: [PATCH] usb: dwc3: host: inherit dma configuration from parent dev
>
> Now not all DMA paremters configured properly for "xhci-hcd" platform
> device which is created manually. For example: dma_pfn_offset, dam_ops
> and iommu configuration will not corresponds "dwc3" devices
> configuration. As result, this will cause problems like wrong DMA
> addresses translation on platforms with LPAE enabled like Keystone 2.
>
> When platform is using DT boot mode the DMA configuration will be
> parsed and applied from DT, so, to fix this issue, reuse
> of_dma_configure() API and retrieve DMA configuartion for "xhci-hcd"
> from DWC3 device node.
>
> Signed-off-by: Grygorii Strashko <grygorii.strashko@xxxxxx>
> ---
> drivers/usb/dwc3/host.c | 15 ++++++++++-----
> 1 file changed, 10 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/usb/dwc3/host.c b/drivers/usb/dwc3/host.c
> index c679f63..93c8ef9 100644
> --- a/drivers/usb/dwc3/host.c
> +++ b/drivers/usb/dwc3/host.c
> @@ -17,6 +17,7 @@
>
> #include <linux/platform_device.h>
> #include <linux/usb/xhci_pdriver.h>
> +#include <linux/of_device.h>
>
> #include "core.h"
>
> @@ -32,12 +33,7 @@ int dwc3_host_init(struct dwc3 *dwc)
> return -ENOMEM;
> }
>
> - dma_set_coherent_mask(&xhci->dev, dwc->dev->coherent_dma_mask);
> -
> xhci->dev.parent = dwc->dev;
> - xhci->dev.dma_mask = dwc->dev->dma_mask;
> - xhci->dev.dma_parms = dwc->dev->dma_parms;
> -
> dwc->xhci = xhci;
>
> ret = platform_device_add_resources(xhci, dwc->xhci_resources,
> @@ -62,6 +58,15 @@ int dwc3_host_init(struct dwc3 *dwc)
> phy_create_lookup(dwc->usb3_generic_phy, "usb3-phy",
> dev_name(&xhci->dev));
>
> + if (IS_ENABLED(CONFIG_OF) && dwc->dev->of_node) {
> + of_dma_configure(&xhci->dev, dwc->dev->of_node);
> + } else {
> + dma_set_coherent_mask(&xhci->dev, dwc->dev->coherent_dma_mask);
> +
> + xhci->dev.dma_mask = dwc->dev->dma_mask;
> + xhci->dev.dma_parms = dwc->dev->dma_parms;
> + }
> +
> ret = platform_device_add(xhci);
This looks fine to me, though I wonder whether we can make this more
generic so that we don't have to update each driver.
Question for Arnd: would it make sense to add an of_dma_configure(dev,
dev->parent->of_node) call to platform_device_add() _if_ the device
being added does not have an of_node? Alternatively, this could be done
in the arch code via bus notifiers (we used to have one on arm64 for
cache coherency but I removed it in 2189064795dc ("arm64: Implement
set_arch_dma_coherent_ops() to replace bus notifiers")).
--
Catalin
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