On Tue, Nov 26, 2013 at 08:11:26PM +0800, 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 <[email protected]>
> Acked-by: Alan Stern <[email protected]>
> Signed-off-by: Marc Kleine-Budde <[email protected]>
> ---
> drivers/usb/host/ehci.h | 18 +++++++++++++++++-
> 1 files changed, 17 insertions(+), 1 deletions(-)
>
Hi Greg, will you apply this patch to your 3.13-rcX?
I will take the other two at this patchset.
Peter
> diff --git a/drivers/usb/host/ehci.h b/drivers/usb/host/ehci.h
> index e8f41c5..4a320ab 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 +729,18 @@ static inline unsigned int ehci_readl(const struct
> ehci_hcd *ehci,
> #endif
> }
>
> +#ifdef CONFIG_SOC_IMX28
> +static inline void imx28_ehci_writel(const unsigned int val,
> + volatile __u32 __iomem *addr)
> +{
> + __asm__ ("swp %0, %0, [%1]" : : "r"(val), "r"(addr));
> +}
> +#else
> +static inline void imx28_ehci_writel(const unsigned int val,
> + volatile __u32 __iomem *addr)
> +{
> +}
> +#endif
> static inline void ehci_writel(const struct ehci_hcd *ehci,
> const unsigned int val, __u32 __iomem *regs)
> {
> @@ -736,7 +749,10 @@ static inline void ehci_writel(const struct ehci_hcd
> *ehci,
> writel_be(val, regs) :
> writel(val, regs);
> #else
> - writel(val, regs);
> + if (IS_ENABLED(CONFIG_SOC_IMX28) && ehci->imx28_write_fix)
> + imx28_ehci_writel(val, regs);
> + else
> + writel(val, regs);
> #endif
> }
>
> --
> 1.7.8
>
--
Best Regards,
Peter Chen
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