On Tue, May 07, 2013 at 04:53:52PM -0600, Stephen Warren wrote: > From: Stephen Warren <swarren@xxxxxxxxxx> > > 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@xxxxxxxx> > Signed-off-by: Stephen Warren <swarren@xxxxxxxxxx> So this needs to go in for 3.10, right? Any older kernels as well? If so, which ones? thanks, greg k-h -- 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
