Messages in this thread | | | Date | Wed, 26 Jul 2023 15:25:03 +0530 | Subject | Re: usb: common: usb-conn-gpio: Prevent bailing out if initial role is none | From | Prashanth K <> |
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On 25-07-23 09:04 pm, Greg Kroah-Hartman wrote: > On Thu, Jul 06, 2023 at 03:40:58PM +0530, Prashanth K wrote: >> Currently if we bootup a device without cable connected, then >> usb-conn-gpio won't call set_role() since last_role is same as >> current role. This happens because during probe last_role gets >> initialised to zero. >> >> To avoid this, add a new flag initial_det in usb_conn_info, >> which is used to prevent bailing out during init detection. >> >> Fixes: 4602f3bff266 ("usb: common: add USB GPIO based connection detection driver") >> Signed-off-by: Prashanth K <quic_prashk@quicinc.com> >> --- >> drivers/usb/common/usb-conn-gpio.c | 6 +++++- >> 1 file changed, 5 insertions(+), 1 deletion(-) >> >> diff --git a/drivers/usb/common/usb-conn-gpio.c b/drivers/usb/common/usb-conn-gpio.c >> index 766005d..46290ff 100644 >> --- a/drivers/usb/common/usb-conn-gpio.c >> +++ b/drivers/usb/common/usb-conn-gpio.c >> @@ -42,6 +42,7 @@ struct usb_conn_info { >> >> struct power_supply_desc desc; >> struct power_supply *charger; >> + bool initial_det; > > What does "initial_det" mean? Please document this better. > Yea sure, will update that. It was supposed to mean initial_detection. >> }; >> >> /* >> @@ -86,11 +87,13 @@ static void usb_conn_detect_cable(struct work_struct *work) >> dev_dbg(info->dev, "role %s -> %s, gpios: id %d, vbus %d\n", >> usb_role_string(info->last_role), usb_role_string(role), id, vbus); >> >> - if (info->last_role == role) { >> + if (!info->initial_det && info->last_role == role) { >> dev_warn(info->dev, "repeated role: %s\n", usb_role_string(role)); >> return; >> } >> >> + info->initial_det = false; >> + >> if (info->last_role == USB_ROLE_HOST && info->vbus) >> regulator_disable(info->vbus); >> >> @@ -258,6 +261,7 @@ static int usb_conn_probe(struct platform_device *pdev) >> device_set_wakeup_capable(&pdev->dev, true); >> >> /* Perform initial detection */ >> + info->initial_det = true; > > What is protecting this from changing right after you test for it? > > thanks, > > greg k-h
Hi Greg, this variable is only used/changed by usb_conn_detect_cable() which is called in next line. So the chance of it changing is none. Basically this initial_det flag points if its initial detection or not. If yes, then prevent bailing out in usb_conn_detect_cable(). Please let me know if your comment was regarding something else.
Regards, Prashanth K
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