[PATCH 1/7] usb: ehci-mx6: Add powerup_fixup implementation

[Lukasz Majewski]

Hi Peng, Marek

> From: Ye Li <ye.li at nxp.com>
> 
> When doing port reset, the PR bit of PORTSC1 will be automatically
> cleared by our IP, but standard EHCI needs explicit clear by
> software. The EHCI-HCD driver follow the EHCI specification, so after
> 50ms wait, it clear the PR bit by writting to the PORTSC1 register
> with value loaded before setting PR.
> 
> This sequence is ok for our IP when the delay time is exact. But when
> the timer is slower, some bits like PE, PSPD have been set by
> controller automatically after the PR is automatically cleared. So
> the writing to the PORTSC1 will overwrite these bits set by
> controller. And eventually the driver gets wrong status.
> 
> We implement the powerup_fixup operation which delays 50ms and will
> check the PR until it is cleared by controller. And will update the
> reg value which is written to PORTSC register by EHCI-HCD driver.
> This is much safer than depending on the delay time to be accurate
> and aligining with controller's behaiver.

Is there any plan for a follow up for this patch set?

On my imx6q - kp_tpc70 board I can observe that there are some issues
when trying to read data from USB [*]:

Booting update from usb ...
starting USB...
Bus usb at 2184200: USB EHCI 1.00
scanning bus usb at 2184200 for devices... 2 USB Device(s) found
       scanning usb for storage devices... 1 Storage Device(s) found
EHCI timed out on TD - token=0x1f8c80
EHCI timed out on TD - token=0x1f8c80


Peng do you see similar issue when you test it on your iMX8?

The test is very simple - just put on a pendrive a fitImage and
initramfs and try to boot with it. In my case it will hang at least
once per ten attempts.

Note:

[*] - this is a similar issue to one, which I had on the iMX53
controller. However, Marek's patch fixed it on imx53:

"usb: Keep async schedule running only across mass storage xfers"
SHA1: 31232de07ef2bd97ff67625976eecd97eeb1b



> 
> Signed-off-by: Ye Li <ye.li at nxp.com>
> Signed-off-by: Peng Fan <peng.fan at nxp.com>
> ---
>  drivers/usb/host/ehci-mx6.c | 28 +++++++++++++++++++++++++++-
>  1 file changed, 27 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/usb/host/ehci-mx6.c b/drivers/usb/host/ehci-mx6.c
> index 5f84c7b91d..e654595683 100644
> --- a/drivers/usb/host/ehci-mx6.c
> +++ b/drivers/usb/host/ehci-mx6.c
> @@ -267,6 +267,25 @@ int usb_phy_mode(int port)
>  }
>  #endif
>  
> +static void ehci_mx6_powerup_fixup(struct ehci_ctrl *ctrl, uint32_t
> *status_reg,
> +				   uint32_t *reg)
> +{
> +	u32 result;
> +	int usec = 2000;
> +
> +	mdelay(50);
> +
> +	do {
> +		result = ehci_readl(status_reg);
> +		udelay(5);
> +		if (!(result & EHCI_PS_PR))
> +			break;
> +		usec--;
> +	} while (usec > 0);
> +
> +	*reg = ehci_readl(status_reg);
> +}
> +
>  static void usb_oc_config(int index)
>  {
>  #if defined(CONFIG_MX6)
> @@ -366,6 +385,10 @@ int ehci_mx6_common_init(struct usb_ehci *ehci,
> int index) }
>  
>  #if !CONFIG_IS_ENABLED(DM_USB)
> +static const struct ehci_ops mx6_ehci_ops = {
> +	.powerup_fixup		= ehci_mx6_powerup_fixup,
> +};
> +
>  int ehci_hcd_init(int index, enum usb_init_type init,
>  		struct ehci_hccr **hccr, struct ehci_hcor **hcor)
>  {
> @@ -394,6 +417,8 @@ int ehci_hcd_init(int index, enum usb_init_type
> init, if (ret)
>  		return ret;
>  
> +	ehci_set_controller_priv(index, NULL, &mx6_ehci_ops);
> +
>  	type = board_usb_phy_mode(index);
>  
>  	if (hccr && hcor) {
> @@ -467,7 +492,8 @@ static int mx6_init_after_reset(struct ehci_ctrl
> *dev) }
>  
>  static const struct ehci_ops mx6_ehci_ops = {
> -	.init_after_reset = mx6_init_after_reset
> +	.powerup_fixup		= ehci_mx6_powerup_fixup,
> +	.init_after_reset	= mx6_init_after_reset
>  };
>  
>  static int ehci_usb_phy_mode(struct udevice *dev)




Best regards,

Lukasz Majewski

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