From:   Vasily Khoruzhick <anarsoul@gmail.com>
To:     "David S. Miller" <davem@davemloft.net>,
        Rob Herring <robh+dt@kernel.org>,
        Mark Rutland <mark.rutland@arm.com>,
        Maxime Ripard <maxime.ripard@bootlin.com>,
        Chen-Yu Tsai <wens@csie.org>,
        Marcel Holtmann <marcel@holtmann.org>,
        Johan Hedberg <johan.hedberg@gmail.com>,
        Vasily Khoruzhick <anarsoul@gmail.com>, netdev@vger.kernel.org,
        devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
        linux-bluetooth@vger.kernel.org
Subject: [PATCH 1/8] Bluetooth: Add new quirk for broken local ext features max_page
Date:   Fri, 18 Jan 2019 09:02:25 -0800
Message-Id: <20190118170232.16142-2-anarsoul@gmail.com>
In-Reply-To: <20190118170232.16142-1-anarsoul@gmail.com>
References: <20190118170232.16142-1-anarsoul@gmail.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Sender: linux-bluetooth-owner@vger.kernel.org
Precedence: bulk

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