On Wed, Sep 19, 2012 at 05:00:28PM +0530, Kishon Vijay Abraham I wrote:
> Power-cycling the PHY (partially) decreases the number of transitions to
> "Recovery" state. Hence changed the power up sequence to a partial
> power-up before a full power-up of the PHY.
>
> Signed-off-by: Kishon Vijay Abraham I <kishon@xxxxxx>
> Signed-off-by: Moiz Sonasath <m-sonasath@xxxxxx>
this can be amended to patch 1. Why would you introduce a driver with a
known problem ? ;-)
> ---
> drivers/usb/phy/omap-usb3.c | 43 ++++++++++++++++++++++++++++++++++++------
> include/linux/usb/omap_usb.h | 1 +
> 2 files changed, 38 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/usb/phy/omap-usb3.c b/drivers/usb/phy/omap-usb3.c
> index 26402d5..fb3c5e6 100644
> --- a/drivers/usb/phy/omap-usb3.c
> +++ b/drivers/usb/phy/omap-usb3.c
> @@ -35,13 +35,15 @@ static struct usb_dpll_params omap_usb3_dpll_params[NUM_SYS_CLKS] = {
> };
>
> /**
> - * omap5_usb_phy_power - power on/off the serializer using control module
> + * omap5_usb_phy_partial_powerup - power on the serializer using control module
> * @phy: struct omap_usb *
> - * @on: 0 to off and 1 to on based on powering on or off the PHY
> *
> - * omap_usb3 can call this API to power on or off the PHY.
> + * After the dwc3 module is disabled and enabled again the synchronization
> + * between dwc3 and phy goes bad and the device does not get enumerated
> + * in superspeed mode. After some trials it was found powering up TX and
> + * part of RX PHY helped to solve the issue.
> */
> -static int omap5_usb_phy_power(struct omap_usb *phy, bool on)
> +static int omap5_usb_phy_partial_powerup(struct omap_usb *phy)
> {
> u32 val;
> unsigned long rate;
> @@ -58,10 +60,32 @@ static int omap5_usb_phy_power(struct omap_usb *phy, bool on)
>
> val = readl(phy->control_dev);
>
> + val &= ~(USB_PWRCTL_CLK_CMD_MASK | USB_PWRCTL_CLK_FREQ_MASK);
> + val |= (USB3_PHY_PARTIAL_RX_POWERON | USB3_PHY_TX_RX_POWERON)
> + << USB_PWRCTL_CLK_CMD_SHIFT;
> + val |= rate << USB_PWRCTL_CLK_FREQ_SHIFT;
> +
> + writel(val, phy->control_dev);
> +
> + return 0;
> +}
> +
> +/**
> + * omap5_usb_phy_power - power on/off the serializer using control module
> + * @phy: struct omap_usb *
> + * @on: 0 to off and 1 to on based on powering on or off the PHY
> + *
> + * omap_usb3 can call this API to power on or off the PHY.
> + */
> +static int omap5_usb_phy_power(struct omap_usb *phy, bool on)
> +{
> + u32 val;
> +
> + val = readl(phy->control_dev);
> +
> if (on) {
> - val &= ~(USB_PWRCTL_CLK_CMD_MASK | USB_PWRCTL_CLK_FREQ_MASK);
> + val &= ~USB_PWRCTL_CLK_CMD_MASK;
> val |= USB3_PHY_TX_RX_POWERON << USB_PWRCTL_CLK_CMD_SHIFT;
> - val |= rate << USB_PWRCTL_CLK_FREQ_SHIFT;
> } else {
> val &= ~USB_PWRCTL_CLK_CMD_MASK;
> val |= USB3_PHY_TX_RX_POWEROFF << USB_PWRCTL_CLK_CMD_SHIFT;
> @@ -207,6 +231,13 @@ static int omap_usb3_init(struct usb_phy *x)
> struct omap_usb *phy = phy_to_omapusb(x);
>
> omap_usb_dpll_lock(phy);
> + omap5_usb_phy_partial_powerup(phy);
> + /*
> + * Give enough time for the PHY to partially power-up before
> + * powering it up completely. delay value suggested by the HW
> + * team.
> + */
> + mdelay(100);
why 100 ms ? Has this been measured ? Again, 100 ms is a loooooong time.
Soon enough user will be waiting for a bit over a second to see that
after connecting usb cable, there's activity. We don't want user to
notice that kind of thing ;-)
--
balbi
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