summaryrefslogtreecommitdiffstats
path: root/drivers/usb/host/ehci-tegra.c
diff options
context:
space:
mode:
authorStephen Warren <swarren@nvidia.com>2013-05-07 16:53:52 -0600
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2013-05-16 17:30:52 -0700
commit3b9561e9d9b88eca9d4ed6aab025dec2eeeed501 (patch)
tree6ac9d662f3b7c4ee4411d4fc5103f1226430740a /drivers/usb/host/ehci-tegra.c
parent8ff10bdb14a52e3f25d4ce09e0582a8684c1a6db (diff)
downloadlinux-stable-3b9561e9d9b88eca9d4ed6aab025dec2eeeed501.tar.gz
linux-stable-3b9561e9d9b88eca9d4ed6aab025dec2eeeed501.tar.bz2
linux-stable-3b9561e9d9b88eca9d4ed6aab025dec2eeeed501.zip
USB: set device dma_mask without reference to global data
Many USB host drivers contain code such as: if (!pdev->dev.dma_mask) pdev->dev.dma_mask = &tegra_ehci_dma_mask; ... where tegra_ehci_dma_mask is a global. I suspect this code originated in commit 4a53f4e "USB: ehci-tegra: add probing through device tree" and was simply copied everywhere else. This works fine when the code is built-in, but can cause a crash when the code is in a module. The first module load sets up the dma_mask pointer, but if the module is removed and re-inserted, the value is now non-NULL, and hence is not updated to point at the new location, and hence points at a stale location within the previous module load address, which in turn causes a crash if the pointer is de-referenced. The simplest way of solving this seems to be to copy the code from ehci-platform.c, which uses the coherent_dma_mask as the target for the dma_mask pointer. Suggested-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Stephen Warren <swarren@nvidia.com> Acked-by: Tony Prisk <linux@prisktech.co.nz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/usb/host/ehci-tegra.c')
-rw-r--r--drivers/usb/host/ehci-tegra.c6
1 files changed, 3 insertions, 3 deletions
diff --git a/drivers/usb/host/ehci-tegra.c b/drivers/usb/host/ehci-tegra.c
index e3eddc31ac83..59d111bf44a9 100644
--- a/drivers/usb/host/ehci-tegra.c
+++ b/drivers/usb/host/ehci-tegra.c
@@ -637,8 +637,6 @@ static void tegra_ehci_set_phcd(struct usb_phy *x, bool enable)
writel(val, base + TEGRA_USB_PORTSC1);
}
-static u64 tegra_ehci_dma_mask = DMA_BIT_MASK(32);
-
static int tegra_ehci_probe(struct platform_device *pdev)
{
struct resource *res;
@@ -661,7 +659,9 @@ static int tegra_ehci_probe(struct platform_device *pdev)
* Once we have dma capability bindings this can go away.
*/
if (!pdev->dev.dma_mask)
- pdev->dev.dma_mask = &tegra_ehci_dma_mask;
+ pdev->dev.dma_mask = &pdev->dev.coherent_dma_mask;
+ if (!pdev->dev.coherent_dma_mask)
+ pdev->dev.coherent_dma_mask = DMA_BIT_MASK(32);
setup_vbus_gpio(pdev, pdata);