Any extcon events between the initial state read and ci_extcon_register are
"lost". This patch doesn't fix the issue entirely but reduces the chance of
the controller entering a bad state.
Signed-off-by: Jonathan Marek <jonathan@xxxxxxxx>
---
drivers/usb/chipidea/core.c | 35 +++++++++++++++++++----------------
1 file changed, 19 insertions(+), 16 deletions(-)
diff --git a/drivers/usb/chipidea/core.c b/drivers/usb/chipidea/core.c
index 33ae87f..a1fb2fb 100644
--- a/drivers/usb/chipidea/core.c
+++ b/drivers/usb/chipidea/core.c
@@ -704,25 +704,9 @@ static int ci_get_platdata(struct device *dev,
cable->nb.notifier_call = ci_cable_notifier;
cable->edev = ext_vbus;
- if (!IS_ERR(ext_vbus)) {
- ret = extcon_get_state(cable->edev, EXTCON_USB);
- if (ret)
- cable->connected = true;
- else
- cable->connected = false;
- }
-
cable = &platdata->id_extcon;
cable->nb.notifier_call = ci_cable_notifier;
cable->edev = ext_id;
-
- if (!IS_ERR(ext_id)) {
- ret = extcon_get_state(cable->edev, EXTCON_USB_HOST);
- if (ret)
- cable->connected = true;
- else
- cable->connected = false;
- }
return 0;
}
@@ -892,6 +876,7 @@ static int ci_hdrc_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct ci_hdrc *ci;
+ struct ci_hdrc_cable *cable;
struct resource *res;
void __iomem *base;
int ret;
@@ -1009,6 +994,24 @@ static int ci_hdrc_probe(struct platform_device *pdev)
}
}
+ cable = &ci->platdata->vbus_extcon;
+ if (!IS_ERR(cable->edev)) {
+ ret = extcon_get_state(cable->edev, EXTCON_USB);
+ if (ret)
+ cable->connected = true;
+ else
+ cable->connected = false;
+ }
+
+ cable = &ci->platdata->id_extcon;
+ if (!IS_ERR(cable->edev)) {
+ ret = extcon_get_state(cable->edev, EXTCON_USB_HOST);
+ if (ret)
+ cable->connected = true;
+ else
+ cable->connected = false;
+ }
+
if (ci->roles[CI_ROLE_HOST] && ci->roles[CI_ROLE_GADGET]) {
if (ci->is_otg) {
ci->role = ci_otg_role(ci);
--
2.9.3
On 02/23/2018 10:06 PM, Peter Chen wrote:
Subject: Bugged initial state with Chipidea driver
Hi,
In the Chipidea driver the extcon state is read early in the initialization and
notifications for extcon events are only enabled at the end of the initialization. If the
extcon state changes in between the driver will miss the change in extcon state and
be a bad state.
Yes, it is the limitation, we need to move ci_extcon_register and update extcon state in chipidea driver
before we read ID or VBUS value (through extcon)
Here is what happens in my case:
1. EXTCON_USB_HOST=1, EXTCON_USB=1
Why the two events are both 1 at same time?
2. USB driver reads initial extcon state
3. EXTCON_USB_HOST=0
4. USB driver choses initial role
5. USB driver enables extcon notifiers then the USB driver is stuck
in host mode until the EXTCON_USB_HOST value cycles again, when it should be
in gadget mode. This happens every other boot because my EXTCON_USB_HOST
value is unreliable during init.
I have implemented a temporary solution for myself but if you propose a proper
solution I can implement it and submit a patch.
Feel free to submit your patch.
Additionally, I guess this could technically happen without extcon, but it is much less
likely.
For non-extcon solution, the register (otgsc) reflect real-time vbus and id value, so it
should be without problem you meet.
Peter
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