On Fri, May 18, 2018 at 05:29:40PM +0100, Marc Zyngier wrote: > Back around the 4.13 timeframe, we tried to address a rather bad issue > with the Renesas uPD72020x USB3 controller family. They have trouble > with the programming of the base addresses which tend to stick on XHCI > reset. This makes transitionning from 64bit to 32bit addresses > completely unsafe. This was observed on a fairly popular arm64 > platform (AMD Opteron 1100, which has all of its memory above 4GB). > > The fix was to perform a PCI reset of the device, but we have had > multiple reports that this generated regressions (the controller not > being usable after the patch was applied). On my x86-64 the regression is gone with the removal of the PCI reset, can't say anything about the original issue it was supposed to fix. Tested-by: Domenico Andreoli <domenico.andreoli@xxxxxxxxx> Thank you. Dom > > This series reverts the problematic patch, and tries to address it in > a more constrained way. If the controller is behind an IOMMU (and only > in that case), we zero its base addresses before reseting it. In the > affected configuration, this has the effect of putting the device in a > state where the XHCI reset will be effective. > > It must be noted that in the absence of an IOMMU (and maybe even in > its presence), this device is completely unsafe, and may silently > corrupt memory. > > * From v1: > - Fixed stupid hunk misplacement, now properly moved back to patch 2 > - Converted all quirks to BIT_ULL() > > Marc Zyngier (3): > xhci: Allow more than 32 quirks > xhci: Add quirk to zero 64bit registers on Renesas PCIe controllers > Revert "xhci: Reset Renesas uPD72020x USB controller for 32-bit DMA > issue" > > drivers/usb/host/pci-quirks.c | 20 ------------- > drivers/usb/host/pci-quirks.h | 1 - > drivers/usb/host/xhci-pci.c | 15 ++++------ > drivers/usb/host/xhci.c | 65 +++++++++++++++++++++++++++++++++++++++-- > drivers/usb/host/xhci.h | 67 ++++++++++++++++++++++--------------------- > 5 files changed, 102 insertions(+), 66 deletions(-) > > -- > 2.14.2 > -- 3B10 0CA1 8674 ACBA B4FE FCD2 CE5B CF17 9960 DE13 -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
