Patch "Bluetooth: Add new quirk for broken local ext features page 2" has been added to the 6.3-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    Bluetooth: Add new quirk for broken local ext features page 2

to the 6.3-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     bluetooth-add-new-quirk-for-broken-local-ext-feature.patch
and it can be found in the queue-6.3 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit 9a4c3f46e7754ff092f92bdb27bc0300f1d964ab
Author: Vasily Khoruzhick <anarsoul@xxxxxxxxx>
Date:   Tue Mar 7 23:17:30 2023 +0100

    Bluetooth: Add new quirk for broken local ext features page 2
    
    [ Upstream commit 8194f1ef5a815aea815a91daf2c721eab2674f1f ]
    
    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@xxxxxxxxx>
    Signed-off-by: Bastian Germann <bage@xxxxxxxxxx>
    Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@xxxxxxxxx>
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/include/net/bluetooth/hci.h b/include/net/bluetooth/hci.h
index 400f8a7d0c3fe..997107bfc0b12 100644
--- a/include/net/bluetooth/hci.h
+++ b/include/net/bluetooth/hci.h
@@ -294,6 +294,13 @@ enum {
 	 * during the hdev->setup vendor callback.
 	 */
 	HCI_QUIRK_BROKEN_MWS_TRANSPORT_CONFIG,
+
+	/* 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_FEATURES_PAGE_2,
 };
 
 /* HCI device flags */
diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c
index e87c928c9e17a..51f13518dba9b 100644
--- a/net/bluetooth/hci_event.c
+++ b/net/bluetooth/hci_event.c
@@ -886,8 +886,13 @@ static u8 hci_cc_read_local_ext_features(struct hci_dev *hdev, void *data,
 	if (rp->status)
 		return rp->status;
 
-	if (hdev->max_page < rp->max_page)
-		hdev->max_page = rp->max_page;
+	if (hdev->max_page < rp->max_page) {
+		if (test_bit(HCI_QUIRK_BROKEN_LOCAL_EXT_FEATURES_PAGE_2,
+			     &hdev->quirks))
+			bt_dev_warn(hdev, "broken local ext features page 2");
+		else
+			hdev->max_page = rp->max_page;
+	}
 
 	if (rp->page < HCI_MAX_PAGES)
 		memcpy(hdev->features[rp->page], rp->features, 8);