On Mon, Nov 11, 2013 at 10:32:51PM +0100, Marc Kleine-Budde wrote: > On 10/30/2013 04:06 AM, Peter Chen wrote: > > According to Freescale imx28 Errata, "ENGR119653 USB: ARM to USB > > register error issue", All USB register write operations must > > use the ARM SWP instruction. So, we implement a special ehci_write > > for imx28. > > > > Discussion for it at below: > > http://marc.info/?l=linux-usb&m=137996395529294&w=2 > > > > Signed-off-by: Peter Chen <peter.c...@freescale.com> > > Acked-by: Alan Stern <st...@rowland.harvard.edu> > > --- > > drivers/usb/host/ehci.h | 13 +++++++++++++ > > 1 files changed, 13 insertions(+), 0 deletions(-) > > > > diff --git a/drivers/usb/host/ehci.h b/drivers/usb/host/ehci.h > > index e8f41c5..535aa8b 100644 > > --- a/drivers/usb/host/ehci.h > > +++ b/drivers/usb/host/ehci.h > > @@ -225,6 +225,7 @@ struct ehci_hcd { /* one per > > controller */ > > unsigned has_synopsys_hc_bug:1; /* Synopsys HC */ > > unsigned frame_index_bug:1; /* MosChip (AKA NetMos) */ > > unsigned need_oc_pp_cycle:1; /* MPC834X port power */ > > + unsigned imx28_write_fix:1; /* For Freescale i.MX28 */ > > > > /* required for usb32 quirk */ > > #define OHCI_CTRL_HCFS (3 << 6) > > @@ -728,6 +729,13 @@ static inline unsigned int ehci_readl(const struct > > ehci_hcd *ehci, > > #endif > > } > > > > +#ifdef CONFIG_SOC_IMX28 > > +static inline void imx28_ehci_writel(u32 val32, volatile u32 *addr) > > You should annotate the addr pointer with __iomem, or better use the > signature of ehci_writel(): > > static inline void imx28_ehci_writel(const unsinged int val32, __u32 > __iomem *addr) >
I agree, but volatile is needed as it needs to read/write from io address. -- Best Regards, Peter Chen -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html