summaryrefslogtreecommitdiffstats
path: root/drivers/usb/host/ohci-omap3.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/ohci-omap3.c
parent8ff10bdb14a52e3f25d4ce09e0582a8684c1a6db (diff)
downloadtalos-op-linux-3b9561e9d9b88eca9d4ed6aab025dec2eeeed501.tar.gz
talos-op-linux-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/ohci-omap3.c')
-rw-r--r--drivers/usb/host/ohci-omap3.c8
1 files changed, 4 insertions, 4 deletions
diff --git a/drivers/usb/host/ohci-omap3.c b/drivers/usb/host/ohci-omap3.c
index ddfc31427bc0..8663851c8d8e 100644
--- a/drivers/usb/host/ohci-omap3.c
+++ b/drivers/usb/host/ohci-omap3.c
@@ -114,8 +114,6 @@ static const struct hc_driver ohci_omap3_hc_driver = {
/*-------------------------------------------------------------------------*/
-static u64 omap_ohci_dma_mask = DMA_BIT_MASK(32);
-
/*
* configure so an HC device and id are always provided
* always called with process context; sleeping is OK
@@ -168,8 +166,10 @@ static int ohci_hcd_omap3_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_ohci_dma_mask;
+ if (!dev->dma_mask)
+ dev->dma_mask = &dev->coherent_dma_mask;
+ if (!dev->coherent_dma_mask)
+ dev->coherent_dma_mask = DMA_BIT_MASK(32);
hcd = usb_create_hcd(&ohci_omap3_hc_driver, dev,
dev_name(dev));
OpenPOWER on IntegriCloud