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

Chanwoo Choi
2019-09-20T08:39:22Z

Hi,

On 19. 9. 17. 오전 6:15, Yauhen Kharuzhy 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.
>
> 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);
>

I edit this patch as following by myself and then applied it.

diff --git a/drivers/extcon/extcon-intel-cht-wc.c b/drivers/extcon/extcon-intel-cht-wc.c
index 9d32150e68db..771f6f4cf92e 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;
+ }
+
+ /*
+ * If no USB host or device connected, route D+ and D- to PMIC for
+ * initial charger detection
+ */
+ id = cht_wc_extcon_get_id(ext, pwrsrc_sts);
+ if (id != INTEL_USB_ID_GND)
+ cht_wc_extcon_set_phymux(ext, MUX_SEL_PMIC);

--
Best Regards,
Chanwoo Choi
Samsung Electronics