Re: [PATCH v2 1/2 RESEND] usb: core: phy: add support for PHY calibration

Marek Szyprowski
2019-08-26T08:55:43Z

Hi Greg

On 2019-08-08 11:41, Marek Szyprowski wrote:
> Some PHYs (for example Exynos5 USB3.0 DRD PHY) require calibration to be
> done after every USB HCD reset. Generic PHY framework has been already
> extended with phy_calibrate() function in commit 36914111e682 ("drivers:
> phy: add calibrate method"). This patch adds support for it to generic
> PHY handling code in USB HCD core.
>
> Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
> Tested-by: Anand Moon <linux.amoon@gmail.com>
> Tested-by: Jochen Sprickerhof <jochen@sprickerhof.de>

Greg: any chance to give it this a try in -next? If not, maybe You can
point someone whose review will help?

> ---
> drivers/usb/core/hcd.c | 7 +++++++
> drivers/usb/core/phy.c | 21 +++++++++++++++++++++
> drivers/usb/core/phy.h | 1 +
> 3 files changed, 29 insertions(+)
>
> diff --git a/drivers/usb/core/hcd.c b/drivers/usb/core/hcd.c
> index 88533938ce19..b89936c1df23 100644
> --- a/drivers/usb/core/hcd.c
> +++ b/drivers/usb/core/hcd.c
> @@ -2291,6 +2291,9 @@ int hcd_bus_resume(struct usb_device *rhdev, pm_message_t msg)
> hcd->state = HC_STATE_RESUMING;
> status = hcd->driver->bus_resume(hcd);
> clear_bit(HCD_FLAG_WAKEUP_PENDING, &hcd->flags);
> + if (status == 0)
> + status = usb_phy_roothub_calibrate(hcd->phy_roothub);
> +
> if (status == 0) {
> struct usb_device *udev;
> int port1;
> @@ -2864,6 +2867,10 @@ int usb_add_hcd(struct usb_hcd *hcd,
> }
> hcd->rh_pollable = 1;
>
> + retval = usb_phy_roothub_calibrate(hcd->phy_roothub);
> + if (retval)
> + goto err_hcd_driver_setup;
> +
> /* NOTE: root hub and controller capabilities may not be the same */
> if (device_can_wakeup(hcd->self.controller)
> && device_can_wakeup(&hcd->self.root_hub->dev))
> diff --git a/drivers/usb/core/phy.c b/drivers/usb/core/phy.c
> index 7580493b867a..fb1588e7c282 100644
> --- a/drivers/usb/core/phy.c
> +++ b/drivers/usb/core/phy.c
> @@ -151,6 +151,27 @@ int usb_phy_roothub_set_mode(struct usb_phy_roothub *phy_roothub,
> }
> EXPORT_SYMBOL_GPL(usb_phy_roothub_set_mode);
>
> +int usb_phy_roothub_calibrate(struct usb_phy_roothub *phy_roothub)
> +{
> + struct usb_phy_roothub *roothub_entry;
> + struct list_head *head;
> + int err;
> +
> + if (!phy_roothub)
> + return 0;
> +
> + head = &phy_roothub->list;
> +
> + list_for_each_entry(roothub_entry, head, list) {
> + err = phy_calibrate(roothub_entry->phy);
> + if (err)
> + return err;
> + }
> +
> + return 0;
> +}
> +EXPORT_SYMBOL_GPL(usb_phy_roothub_calibrate);
> +
> int usb_phy_roothub_power_on(struct usb_phy_roothub *phy_roothub)
> {
> struct usb_phy_roothub *roothub_entry;
> diff --git a/drivers/usb/core/phy.h b/drivers/usb/core/phy.h
> index dad564e2d2d4..20a267cd986b 100644
> --- a/drivers/usb/core/phy.h
> +++ b/drivers/usb/core/phy.h
> @@ -18,6 +18,7 @@ int usb_phy_roothub_exit(struct usb_phy_roothub *phy_roothub);
>
> int usb_phy_roothub_set_mode(struct usb_phy_roothub *phy_roothub,
> enum phy_mode mode);
> +int usb_phy_roothub_calibrate(struct usb_phy_roothub *phy_roothub);
> int usb_phy_roothub_power_on(struct usb_phy_roothub *phy_roothub);
> void usb_phy_roothub_power_off(struct usb_phy_roothub *phy_roothub);
>

Best regards
--
Marek Szyprowski, PhD
Samsung R&D Institute Poland