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SubjectRE: [PATCH v2] fsl/usb: Workarourd for USB erratum-A005697
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Thanks a lot  for you look into this patch, I will fixed these typos.


Best Regards
Jerry Huang


-----Original Message-----
From: Sergei Shtylyov [mailto:sergei.shtylyov@cogentembedded.com]
Sent: Friday, November 25, 2016 9:12 PM
To: Jerry Huang <jerry.huang@nxp.com>; stern@rowland.harvard.edu; gregkh@linuxfoundation.org
Cc: Ramneek Mehresh <ramneek.mehresh@nxp.com>; julia.lawall@lip6.fr; Sriram Dash <sriram.dash@nxp.com>; linux-usb@vger.kernel.org; linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2] fsl/usb: Workarourd for USB erratum-A005697

Hello.

On 11/25/2016 06:24 AM, Changming Huang wrote:

> The EHCI specification states the following in the SUSP bit description:
> In the Suspend state, the port is senstive to resume detection.

Sensitive.

> Note that the bit status does not change untile the port is suspended
> and

Until.

> that there may be a delay in susupending a port if there is a
> transaction

Suspending.

> currently in progress on the USB.
>
> However, in NXP USBDR controller, the PORTSCx[SUSP] bit changes
> immediately when the application sets it and not when the port is actually suspended.
>
> So the application must wait for at least 10 milliseconds after a port
> indicates that it is suspended, to make sure this port has entered
> suspended state before initiating this port resume using the Force
> Port Resume bit. This bit is for NXP controller, not EHCI compatible.
>
> Signed-off-by: Changming Huang <jerry.huang@nxp.com>
> Signed-off-by: Ramneek Mehresh <ramneek.mehresh@nxp.com>

[...]

> diff --git a/drivers/usb/host/ehci-hub.c b/drivers/usb/host/ehci-hub.c
> index 74f62d6..81e2310 100644
> --- a/drivers/usb/host/ehci-hub.c
> +++ b/drivers/usb/host/ehci-hub.c
> @@ -310,6 +310,13 @@ static int ehci_bus_suspend (struct usb_hcd *hcd)
> }
> spin_unlock_irq(&ehci->lock);
>
> + if (changed && ehci_has_fsl_susp_errata(ehci))
> + /* Wait for at least 10 millisecondes to ensure the controller

Milliseconds.

> + * enter the suspend status before initiating a port resume
> + * using the Fore Port Resume bit (Not-EHCI compatible).

Maybe force?
s/Not/non/ also.

> + */
> + usleep_range(10000, 20000);
> +
> if ((changed && ehci->has_tdi_phy_lpm) || fs_idle_delay) {
> /*
> * Wait for HCD to enter low-power mode or for the bus
[...]
> @@ -703,10 +704,15 @@ struct ehci_tt { #if defined(CONFIG_PPC_85xx)
> /* Some Freescale processors have an erratum (USB A-005275) in which
> * incoming packets get corrupted in HS mode
> + * Some Freescale processors have an erratum (USB A-005697) in which
> + * we need to wait for 10ms for bus to fo into suspend mode after

Fo?

[...]

MBR, Sergei

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