Hi Mathias, Would you review this patch? This patch could be applied into the latest usb.git / usb-next branch. Best regards, Yoshihiro Shimoda > -----Original Message----- > From: Yoshihiro Shimoda > Sent: Tuesday, February 16, 2016 12:26 PM > To: mathias.nyman@xxxxxxxxx; gregkh@xxxxxxxxxxxxxxxxxxx > Cc: linux-usb@xxxxxxxxxxxxxxx; linux-renesas-soc@xxxxxxxxxxxxxxx; Yoshihiro Shimoda <yoshihiro.shimoda.uh@xxxxxxxxxxx> > Subject: [PATCH] usb: host: xhci-plat: fix cannot work if R-Car Gen2/3 run on above 4GB phys > > On xHCI controllers of R-Car Gen2 and Gen3, the AC64 bit (bit 0) of > HCCPARAMS1 is set to 1. However, these SoCs don't support 64-bit address > memory pointers. So, this driver should call dma_set_coherent_mask(dev, > DMA_BIT_MASK(32)) in xhci_gen_setup(). Otherwise, the xHCI controller > will be died after a usb device is connected if R-Car Gen2/3 run on above > 4GB physical memory environment. > > This patch adds clearing the AC64 bit of xhci->hcc_params in the > xhci_plat_quirks() to fix the issue. > > Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@xxxxxxxxxxx> > --- > drivers/usb/host/xhci-plat.c | 13 +++++++++++++ > 1 file changed, 13 insertions(+) > > diff --git a/drivers/usb/host/xhci-plat.c b/drivers/usb/host/xhci-plat.c > index d39d6bf..047fb6a 100644 > --- a/drivers/usb/host/xhci-plat.c > +++ b/drivers/usb/host/xhci-plat.c > @@ -39,12 +39,25 @@ static const struct xhci_driver_overrides xhci_plat_overrides __initconst = { > > static void xhci_plat_quirks(struct device *dev, struct xhci_hcd *xhci) > { > + struct usb_hcd *hcd = xhci_to_hcd(xhci); > + > /* > * As of now platform drivers don't provide MSI support so we ensure > * here that the generic code does not try to make a pci_dev from our > * dev struct in order to setup MSI > */ > xhci->quirks |= XHCI_PLAT; > + > + /* > + * On R-Car Gen2 and Gen3, the AC64 bit (bit 0) of HCCPARAMS1 is set > + * to 1. However, these SoCs don't support 64-bit address memory > + * pointers. So, this driver clears the AC64 bit of xhci->hcc_params > + * to call dma_set_coherent_mask(dev, DMA_BIT_MASK(32)) in > + * xhci_gen_setup(). > + */ > + if (xhci_plat_type_is(hcd, XHCI_PLAT_TYPE_RENESAS_RCAR_GEN2) || > + xhci_plat_type_is(hcd, XHCI_PLAT_TYPE_RENESAS_RCAR_GEN3)) > + xhci->hcc_params &= ~BIT(0); /* clear HCC_64BIT_ADDR */ > } > > /* called during probe() after chip reset completes */ > -- > 1.9.1