Re: [PATCH 2/2] Bluetooth: mediatek: fix the conflict between mtk and msft vendor event

From: kernel test robot
Date: Mon Feb 14 2022 - 03:53:00 EST


Hi Sean,

Thanks for your patch! Perhaps something to improve:

[auto build test WARNING on bluetooth-next/master]
[also build test WARNING on next-20220211]
[cannot apply to v5.17-rc3]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]

url: https://github.com/0day-ci/linux/commits/sean-wang-mediatek-com/Bluetooth-mt7921s-support-bluetooth-reset-mechanism/20220129-140313
base: https://git.kernel.org/pub/scm/linux/kernel/git/bluetooth/bluetooth-next.git master
config: riscv-randconfig-c006-20220205 (https://download.01.org/0day-ci/archive/20220213/202202130806.UHxKw5N3-lkp@xxxxxxxxx/config)
compiler: clang version 15.0.0 (https://github.com/llvm/llvm-project dee058c670593b999fec19c458dbbd882ad9de56)
reproduce (this is a W=1 build):
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# install riscv cross compiling tool for clang build
# apt-get install binutils-riscv64-linux-gnu
# https://github.com/0day-ci/linux/commit/33092fd43b74594bae07555a6fdf15133cc8ec54
git remote add linux-review https://github.com/0day-ci/linux
git fetch --no-tags linux-review sean-wang-mediatek-com/Bluetooth-mt7921s-support-bluetooth-reset-mechanism/20220129-140313
git checkout 33092fd43b74594bae07555a6fdf15133cc8ec54
# save the config file to linux build tree
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=riscv clang-analyzer

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <yujie.liu@xxxxxxxxx>


clang-analyzer warnings: (new ones prefixed by >>)

>> drivers/bluetooth/btusb.c:2273:3: warning: Value stored to 'hdr' is never read [clang-analyzer-deadcode.DeadStores]
hdr = (void *)skb->data;
^ ~~~~~~~~~~~~~~~~~

vim +/hdr +2273 drivers/bluetooth/btusb.c

5a87679ffd4436 mark-yw.chen 2021-09-01 2248
a1c49c434e1505 Sean Wang 2019-06-02 2249 static void btusb_mtk_wmt_recv(struct urb *urb)
a1c49c434e1505 Sean Wang 2019-06-02 2250 {
a1c49c434e1505 Sean Wang 2019-06-02 2251 struct hci_dev *hdev = urb->context;
a1c49c434e1505 Sean Wang 2019-06-02 2252 struct btusb_data *data = hci_get_drvdata(hdev);
a1c49c434e1505 Sean Wang 2019-06-02 @2253 struct hci_event_hdr *hdr;
a1c49c434e1505 Sean Wang 2019-06-02 2254 struct sk_buff *skb;
a1c49c434e1505 Sean Wang 2019-06-02 2255 int err;
a1c49c434e1505 Sean Wang 2019-06-02 2256
a1c49c434e1505 Sean Wang 2019-06-02 2257 if (urb->status == 0 && urb->actual_length > 0) {
a1c49c434e1505 Sean Wang 2019-06-02 2258 hdev->stat.byte_rx += urb->actual_length;
a1c49c434e1505 Sean Wang 2019-06-02 2259
a1c49c434e1505 Sean Wang 2019-06-02 2260 /* WMT event shouldn't be fragmented and the size should be
a1c49c434e1505 Sean Wang 2019-06-02 2261 * less than HCI_WMT_MAX_EVENT_SIZE.
a1c49c434e1505 Sean Wang 2019-06-02 2262 */
a1c49c434e1505 Sean Wang 2019-06-02 2263 skb = bt_skb_alloc(HCI_WMT_MAX_EVENT_SIZE, GFP_ATOMIC);
a1c49c434e1505 Sean Wang 2019-06-02 2264 if (!skb) {
a1c49c434e1505 Sean Wang 2019-06-02 2265 hdev->stat.err_rx++;
60c6a63a3d3080 Mark-YW.Chen 2021-10-14 2266 kfree(urb->setup_packet);
de71a6cb4bf24d Jupeng Zhong 2021-02-02 2267 return;
a1c49c434e1505 Sean Wang 2019-06-02 2268 }
a1c49c434e1505 Sean Wang 2019-06-02 2269
a1c49c434e1505 Sean Wang 2019-06-02 2270 hci_skb_pkt_type(skb) = HCI_EVENT_PKT;
a1c49c434e1505 Sean Wang 2019-06-02 2271 skb_put_data(skb, urb->transfer_buffer, urb->actual_length);
a1c49c434e1505 Sean Wang 2019-06-02 2272
a1c49c434e1505 Sean Wang 2019-06-02 @2273 hdr = (void *)skb->data;
a1c49c434e1505 Sean Wang 2019-06-02 2274
a1c49c434e1505 Sean Wang 2019-06-02 2275 /* When someone waits for the WMT event, the skb is being cloned
a1c49c434e1505 Sean Wang 2019-06-02 2276 * and being processed the events from there then.
a1c49c434e1505 Sean Wang 2019-06-02 2277 */
a1c49c434e1505 Sean Wang 2019-06-02 2278 if (test_bit(BTUSB_TX_WAIT_VND_EVT, &data->flags)) {
22cc6b7a1dbb58 Johan Hovold 2019-11-28 2279 data->evt_skb = skb_clone(skb, GFP_ATOMIC);
de71a6cb4bf24d Jupeng Zhong 2021-02-02 2280 if (!data->evt_skb) {
de71a6cb4bf24d Jupeng Zhong 2021-02-02 2281 kfree_skb(skb);
60c6a63a3d3080 Mark-YW.Chen 2021-10-14 2282 kfree(urb->setup_packet);
de71a6cb4bf24d Jupeng Zhong 2021-02-02 2283 return;
de71a6cb4bf24d Jupeng Zhong 2021-02-02 2284 }
a1c49c434e1505 Sean Wang 2019-06-02 2285 }
a1c49c434e1505 Sean Wang 2019-06-02 2286
a1c49c434e1505 Sean Wang 2019-06-02 2287 err = hci_recv_frame(hdev, skb);
de71a6cb4bf24d Jupeng Zhong 2021-02-02 2288 if (err < 0) {
de71a6cb4bf24d Jupeng Zhong 2021-02-02 2289 kfree_skb(data->evt_skb);
de71a6cb4bf24d Jupeng Zhong 2021-02-02 2290 data->evt_skb = NULL;
60c6a63a3d3080 Mark-YW.Chen 2021-10-14 2291 kfree(urb->setup_packet);
de71a6cb4bf24d Jupeng Zhong 2021-02-02 2292 return;
de71a6cb4bf24d Jupeng Zhong 2021-02-02 2293 }
a1c49c434e1505 Sean Wang 2019-06-02 2294
a1c49c434e1505 Sean Wang 2019-06-02 2295 if (test_and_clear_bit(BTUSB_TX_WAIT_VND_EVT,
a1c49c434e1505 Sean Wang 2019-06-02 2296 &data->flags)) {
a1c49c434e1505 Sean Wang 2019-06-02 2297 /* Barrier to sync with other CPUs */
a1c49c434e1505 Sean Wang 2019-06-02 2298 smp_mb__after_atomic();
a1c49c434e1505 Sean Wang 2019-06-02 2299 wake_up_bit(&data->flags,
a1c49c434e1505 Sean Wang 2019-06-02 2300 BTUSB_TX_WAIT_VND_EVT);
a1c49c434e1505 Sean Wang 2019-06-02 2301 }
60c6a63a3d3080 Mark-YW.Chen 2021-10-14 2302 kfree(urb->setup_packet);
a1c49c434e1505 Sean Wang 2019-06-02 2303 return;
a1c49c434e1505 Sean Wang 2019-06-02 2304 } else if (urb->status == -ENOENT) {
a1c49c434e1505 Sean Wang 2019-06-02 2305 /* Avoid suspend failed when usb_kill_urb */
a1c49c434e1505 Sean Wang 2019-06-02 2306 return;
a1c49c434e1505 Sean Wang 2019-06-02 2307 }
a1c49c434e1505 Sean Wang 2019-06-02 2308
a1c49c434e1505 Sean Wang 2019-06-02 2309 usb_mark_last_busy(data->udev);
a1c49c434e1505 Sean Wang 2019-06-02 2310
a1c49c434e1505 Sean Wang 2019-06-02 2311 /* The URB complete handler is still called with urb->actual_length = 0
a1c49c434e1505 Sean Wang 2019-06-02 2312 * when the event is not available, so we should keep re-submitting
a1c49c434e1505 Sean Wang 2019-06-02 2313 * URB until WMT event returns, Also, It's necessary to wait some time
a1c49c434e1505 Sean Wang 2019-06-02 2314 * between the two consecutive control URBs to relax the target device
a1c49c434e1505 Sean Wang 2019-06-02 2315 * to generate the event. Otherwise, the WMT event cannot return from
a1c49c434e1505 Sean Wang 2019-06-02 2316 * the device successfully.
a1c49c434e1505 Sean Wang 2019-06-02 2317 */
48c13301e6baba Mark Chen 2021-02-02 2318 udelay(500);
a1c49c434e1505 Sean Wang 2019-06-02 2319
a1c49c434e1505 Sean Wang 2019-06-02 2320 usb_anchor_urb(urb, &data->ctrl_anchor);
a1c49c434e1505 Sean Wang 2019-06-02 2321 err = usb_submit_urb(urb, GFP_ATOMIC);
a1c49c434e1505 Sean Wang 2019-06-02 2322 if (err < 0) {
60c6a63a3d3080 Mark-YW.Chen 2021-10-14 2323 kfree(urb->setup_packet);
a1c49c434e1505 Sean Wang 2019-06-02 2324 /* -EPERM: urb is being killed;
a1c49c434e1505 Sean Wang 2019-06-02 2325 * -ENODEV: device got disconnected
a1c49c434e1505 Sean Wang 2019-06-02 2326 */
a1c49c434e1505 Sean Wang 2019-06-02 2327 if (err != -EPERM && err != -ENODEV)
a1c49c434e1505 Sean Wang 2019-06-02 2328 bt_dev_err(hdev, "urb %p failed to resubmit (%d)",
a1c49c434e1505 Sean Wang 2019-06-02 2329 urb, -err);
a1c49c434e1505 Sean Wang 2019-06-02 2330 usb_unanchor_urb(urb);
a1c49c434e1505 Sean Wang 2019-06-02 2331 }
a1c49c434e1505 Sean Wang 2019-06-02 2332 }
a1c49c434e1505 Sean Wang 2019-06-02 2333

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