[PATCH 1/8] Bluetooth: Add new quirk for broken local ext features max_page

Vasily Khoruzhick
2019-01-18T17:02:25Z

Some adapters (e.g. RTL8723CS) advertise that they have more than
2 pages for local ext features, but they don't support any features
declared in these pages. RTL8723CS reports max_page = 2 and declares
support for sync train and secure connection, but it responds with
either garbage or with error in status on corresponding commands.

Signed-off-by: Vasily Khoruzhick <anarsoul@gmail.com>
---
include/net/bluetooth/hci.h | 7 +++++++
net/bluetooth/hci_event.c | 4 +++-
2 files changed, 10 insertions(+), 1 deletion(-)

diff --git a/include/net/bluetooth/hci.h b/include/net/bluetooth/hci.h
index c36dc1e20556..d7849f128d58 100644
--- a/include/net/bluetooth/hci.h
+++ b/include/net/bluetooth/hci.h
@@ -192,6 +192,13 @@ enum {
*
*/
HCI_QUIRK_NON_PERSISTENT_SETUP,
+
+ /* When this quirk is set, max_page for local extended features
+ * is set to 1, even if controller reports higher number. Some
+ * controllers (e.g. RTL8723CS) report more pages, but they
+ * don't actually support features declared there.
+ */
+ HCI_QUIRK_BROKEN_LOCAL_EXT_FTR_MAX_PAGE,
};

/* HCI device flags */
diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c
index ac2826ce162b..9c59af7de197 100644
--- a/net/bluetooth/hci_event.c
+++ b/net/bluetooth/hci_event.c
@@ -639,7 +639,9 @@ static void hci_cc_read_local_ext_features(struct hci_dev *hdev,
if (rp->status)
return;

- if (hdev->max_page < rp->max_page)
+ if (!test_bit(HCI_QUIRK_BROKEN_LOCAL_EXT_FTR_MAX_PAGE,
+ &hdev->quirks) &&
+ hdev->max_page < rp->max_page)
hdev->max_page = rp->max_page;

if (rp->page < HCI_MAX_PAGES)
--
2.20.1