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 <[email protected]>
---
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;
};
/*
@@ -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;
usb_conn_queue_dwork(info, 0);
return 0;
--
2.7.4
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 <[email protected]>
> ---
> 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.
> };
>
> /*
> @@ -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
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 <[email protected]>
>> ---
>> 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