Re: [PATCH v2] extcon-intel-cht-wc: Don't reset USB data connection at probe

Andy Shevchenko
2019-09-20T08:26:00Z

On Tue, Sep 17, 2019 at 10:29 AM Yauhen Kharuzhy <jekhor@gmail.com> wrote:
>
> Intel Cherry Trail Whiskey Cove extcon driver connect USB data lines to
> PMIC at driver probing for further charger detection. This causes reset of
> USB data sessions and removing all devices from bus. If system was
> booted from Live CD or USB dongle, this makes system unusable.
>
> Check if USB ID pin is floating and re-route data lines in this case
> only, don't touch otherwise.
>

FWIW,
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>

> Signed-off-by: Yauhen Kharuzhy <jekhor@gmail.com>
> ---
> drivers/extcon/extcon-intel-cht-wc.c | 16 ++++++++++++++--
> 1 file changed, 14 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/extcon/extcon-intel-cht-wc.c b/drivers/extcon/extcon-intel-cht-wc.c
> index 9d32150e68db..da1886a92f75 100644
> --- a/drivers/extcon/extcon-intel-cht-wc.c
> +++ b/drivers/extcon/extcon-intel-cht-wc.c
> @@ -338,6 +338,7 @@ static int cht_wc_extcon_probe(struct platform_device *pdev)
> struct intel_soc_pmic *pmic = dev_get_drvdata(pdev->dev.parent);
> struct cht_wc_extcon_data *ext;
> unsigned long mask = ~(CHT_WC_PWRSRC_VBUS | CHT_WC_PWRSRC_USBID_MASK);
> + int pwrsrc_sts, id;
> int irq, ret;
>
> irq = platform_get_irq(pdev, 0);
> @@ -387,8 +388,19 @@ static int cht_wc_extcon_probe(struct platform_device *pdev)
> goto disable_sw_control;
> }
>
> - /* Route D+ and D- to PMIC for initial charger detection */
> - cht_wc_extcon_set_phymux(ext, MUX_SEL_PMIC);
> + ret = regmap_read(ext->regmap, CHT_WC_PWRSRC_STS, &pwrsrc_sts);
> + if (ret) {
> + dev_err(ext->dev, "Error reading pwrsrc status: %d\n", ret);
> + goto disable_sw_control;
> + }
> +
> + id = cht_wc_extcon_get_id(ext, pwrsrc_sts);
> +
> + /* If no USB host or device connected, route D+ and D- to PMIC for
> + * initial charger detection
> + */
> + if (id != INTEL_USB_ID_GND)
> + cht_wc_extcon_set_phymux(ext, MUX_SEL_PMIC);
>
> /* Get initial state */
> cht_wc_extcon_pwrsrc_event(ext);
> --
> 2.23.0.rc1
>

--
With Best Regards,
Andy Shevchenko