| Message ID | 20201123101308.7291-3-hdegoede@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Bluetooth: btusb: 2 fixes for handling of fake CSR USB dongles | expand |
Hi, On 11/23/20 11:13 AM, Hans de Goede wrote: > With the recent btusb change to detect and deal with more fake CSR > controllers, I decided to see if one of the fakes which I have > lying around would now work. > > After much experimentation I came to the conclusion that it works, if I > have autosuspend enabled initially and then disable it after the device > has suspended at least once. Yes this is very weird, but I've tried many > things, like manually clearing the remote-wakeup feature. Doing a > runtime-resume + runtime suspend is the only way to get the receiver > to actually report received data (and/or pairing info) through its > bulk rx endpoint. > > But the funkyness of the bulk-endpoint does not stop there, I mainly > found out about this problem, because with autosuspend enabled > (which usually ensures the suspend at least once condition is met), > the receiver stops reporting received data through its bulk rx endpoint > as soon as autosuspend kicks in. So I initially just disabled > autosuspend, but then the receiver does not work at all. > > This was with a fake CSR receiver with a bcdDevice value of 0x8891, > a lmp_subver of 0x0x1012, a hci_rev of 0x0810 and a hci_ver of > BLUETOOTH_VER_4_0. I just realized that I should have opened this one and add the chipmarkings to the commit msg here too. So I've just opened it and took a look. This one has a Barrot 8041a02 chip and searching for 8041a92 shows that the internet is full of reports of how crappy it is. I guess this patch probably will get some review remarks anyways, but let me know if you want a v3 with just the chip added to the commit msg. Regards, Hans > > Summarizing this specific fake CSR receiver has the following 2 issues: > > 1. The bulk rx endpoint will never report any data unless > the device was suspended at least once. > > 2. They will not wakeup when autosuspended and receiving data on their > bulk rx endpoint from e.g. a keyboard or mouse (IOW remote-wakeup support > is broken for the bulk endpoint). > > Add a workaround for 1. which enables runtime-suspend, force-suspends > the hci and then wakes-it up by disabling runtime-suspend again. > > Add a workaround for 2. which clears the hci's can_wake flag, this way > the hci will still be autosuspended when it is not open. > > Signed-off-by: Hans de Goede <hdegoede@redhat.com> > --- > drivers/bluetooth/btusb.c | 32 ++++++++++++++++++++++++++++++++ > 1 file changed, 32 insertions(+) > > diff --git a/drivers/bluetooth/btusb.c b/drivers/bluetooth/btusb.c > index ac7fede4f951..48e404dfa246 100644 > --- a/drivers/bluetooth/btusb.c > +++ b/drivers/bluetooth/btusb.c > @@ -1768,6 +1768,7 @@ static int btusb_setup_csr(struct hci_dev *hdev) > struct hci_rp_read_local_version *rp; > struct sk_buff *skb; > bool is_fake = false; > + int ret; > > BT_DBG("%s", hdev->name); > > @@ -1856,6 +1857,37 @@ static int btusb_setup_csr(struct hci_dev *hdev) > */ > clear_bit(HCI_QUIRK_RESET_ON_CLOSE, &hdev->quirks); > clear_bit(HCI_QUIRK_SIMULTANEOUS_DISCOVERY, &hdev->quirks); > + > + /* > + * Some of these clones are really messed-up: > + * 1. Their bulk rx endpoint will never report any data unless > + * the device was suspended at least once (yes really). > + * 2. They will not wakeup when autosuspended and receiving data > + * on their bulk rx endpoint from e.g. a keyboard or mouse > + * (IOW remote-wakeup support is broken for the bulk endpoint). > + * > + * To fix 1. enable runtime-suspend, force-suspend the > + * hci and then wake-it up by disabling runtime-suspend. > + * > + * To fix 2. clear the hci's can_wake flag, this way the hci > + * will still be autosuspended when it is not open. > + */ > + if (device_can_wakeup(&data->udev->dev)) { > + pm_runtime_allow(&data->udev->dev); > + > + ret = pm_runtime_suspend(&data->udev->dev); > + if (ret >= 0) > + msleep(200); > + else > + bt_dev_warn(hdev, "Failed to suspend the device for CSR clone receive-issue workaround\n"); > + > + pm_runtime_forbid(&data->udev->dev); > + > + device_set_wakeup_capable(&data->udev->dev, false); > + /* Re-enable autosuspend if this was requested */ > + if (enable_autosuspend) > + usb_enable_autosuspend(data->udev); > + } > } > > kfree_skb(skb); >
Hi Hans, >> With the recent btusb change to detect and deal with more fake CSR >> controllers, I decided to see if one of the fakes which I have >> lying around would now work. >> >> After much experimentation I came to the conclusion that it works, if I >> have autosuspend enabled initially and then disable it after the device >> has suspended at least once. Yes this is very weird, but I've tried many >> things, like manually clearing the remote-wakeup feature. Doing a >> runtime-resume + runtime suspend is the only way to get the receiver >> to actually report received data (and/or pairing info) through its >> bulk rx endpoint. >> >> But the funkyness of the bulk-endpoint does not stop there, I mainly >> found out about this problem, because with autosuspend enabled >> (which usually ensures the suspend at least once condition is met), >> the receiver stops reporting received data through its bulk rx endpoint >> as soon as autosuspend kicks in. So I initially just disabled >> autosuspend, but then the receiver does not work at all. >> >> This was with a fake CSR receiver with a bcdDevice value of 0x8891, >> a lmp_subver of 0x0x1012, a hci_rev of 0x0810 and a hci_ver of >> BLUETOOTH_VER_4_0. > > I just realized that I should have opened this one and add the > chipmarkings to the commit msg here too. So I've just opened it > and took a look. > > This one has a Barrot 8041a02 chip and searching for 8041a92 shows that > the internet is full of reports of how crappy it is. > > I guess this patch probably will get some review remarks anyways, > but let me know if you want a v3 with just the chip added to the > commit msg. yes please. The more info we add the better. Regards Marcel
diff --git a/drivers/bluetooth/btusb.c b/drivers/bluetooth/btusb.c index ac7fede4f951..48e404dfa246 100644 --- a/drivers/bluetooth/btusb.c +++ b/drivers/bluetooth/btusb.c @@ -1768,6 +1768,7 @@ static int btusb_setup_csr(struct hci_dev *hdev) struct hci_rp_read_local_version *rp; struct sk_buff *skb; bool is_fake = false; + int ret; BT_DBG("%s", hdev->name); @@ -1856,6 +1857,37 @@ static int btusb_setup_csr(struct hci_dev *hdev) */ clear_bit(HCI_QUIRK_RESET_ON_CLOSE, &hdev->quirks); clear_bit(HCI_QUIRK_SIMULTANEOUS_DISCOVERY, &hdev->quirks); + + /* + * Some of these clones are really messed-up: + * 1. Their bulk rx endpoint will never report any data unless + * the device was suspended at least once (yes really). + * 2. They will not wakeup when autosuspended and receiving data + * on their bulk rx endpoint from e.g. a keyboard or mouse + * (IOW remote-wakeup support is broken for the bulk endpoint). + * + * To fix 1. enable runtime-suspend, force-suspend the + * hci and then wake-it up by disabling runtime-suspend. + * + * To fix 2. clear the hci's can_wake flag, this way the hci + * will still be autosuspended when it is not open. + */ + if (device_can_wakeup(&data->udev->dev)) { + pm_runtime_allow(&data->udev->dev); + + ret = pm_runtime_suspend(&data->udev->dev); + if (ret >= 0) + msleep(200); + else + bt_dev_warn(hdev, "Failed to suspend the device for CSR clone receive-issue workaround\n"); + + pm_runtime_forbid(&data->udev->dev); + + device_set_wakeup_capable(&data->udev->dev, false); + /* Re-enable autosuspend if this was requested */ + if (enable_autosuspend) + usb_enable_autosuspend(data->udev); + } } kfree_skb(skb);
With the recent btusb change to detect and deal with more fake CSR controllers, I decided to see if one of the fakes which I have lying around would now work. After much experimentation I came to the conclusion that it works, if I have autosuspend enabled initially and then disable it after the device has suspended at least once. Yes this is very weird, but I've tried many things, like manually clearing the remote-wakeup feature. Doing a runtime-resume + runtime suspend is the only way to get the receiver to actually report received data (and/or pairing info) through its bulk rx endpoint. But the funkyness of the bulk-endpoint does not stop there, I mainly found out about this problem, because with autosuspend enabled (which usually ensures the suspend at least once condition is met), the receiver stops reporting received data through its bulk rx endpoint as soon as autosuspend kicks in. So I initially just disabled autosuspend, but then the receiver does not work at all. This was with a fake CSR receiver with a bcdDevice value of 0x8891, a lmp_subver of 0x0x1012, a hci_rev of 0x0810 and a hci_ver of BLUETOOTH_VER_4_0. Summarizing this specific fake CSR receiver has the following 2 issues: 1. The bulk rx endpoint will never report any data unless the device was suspended at least once. 2. They will not wakeup when autosuspended and receiving data on their bulk rx endpoint from e.g. a keyboard or mouse (IOW remote-wakeup support is broken for the bulk endpoint). Add a workaround for 1. which enables runtime-suspend, force-suspends the hci and then wakes-it up by disabling runtime-suspend again. Add a workaround for 2. which clears the hci's can_wake flag, this way the hci will still be autosuspended when it is not open. Signed-off-by: Hans de Goede <hdegoede@redhat.com> --- drivers/bluetooth/btusb.c | 32 ++++++++++++++++++++++++++++++++ 1 file changed, 32 insertions(+)