Lorenzo Bianconi <lorenzo@xxxxxxxxxx> writes: >> Hi, >> >> I ran into some bug messages while testing linux-next on a MT8186 >> Magneton Chromebook (mt8186-corsola-magneton-sku393218). It boots >> to the OS, but at least Wi-Fi and Bluetooth are unavailable. >> >> As a start, I tried reverting commit abbd838c579e ("Merge tag >> 'mt76-for-kvalo-2024-09-06' of https://github.com/nbd168/wireless") >> and it works fine after that. Didn't have time to do a full bisect, >> but will try if nobody has any immediate opinions. >> >> There are a few traces, here's some select lines to catch your attention, >> not sure how informational they are: >> >> [ 16.040525] kernel BUG at net/core/skbuff.c:2268! >> [ 16.040531] Internal error: Oops - BUG: 00000000f2000800 [#1] SMP >> [ 16.040803] CPU: 3 UID: 0 PID: 526 Comm: mt76-sdio-txrx Not tainted >> 6.11.0-next-20240916-deb-00002-g7b544e01c649 #1 >> [ 16.040897] Call trace: >> [ 16.040899] pskb_expand_head+0x2b0/0x3c0 >> [ 16.040905] mt76s_tx_run_queue+0x274/0x410 [mt76_sdio] >> [ 16.040909] mt76s_txrx_worker+0xe4/0xac8 [mt76_sdio] >> [ 16.040914] mt7921s_txrx_worker+0x98/0x1e0 [mt7921s] >> [ 16.040924] __mt76_worker_fn+0x80/0x128 [mt76] >> [ 16.040934] kthread+0xe8/0xf8 >> [ 16.040940] ret_from_fork+0x10/0x20 > > Hi, > > I guess this issue has been introduced by the following commit: > > commit 3688c18b65aeb2a1f2fde108400afbab129a8cc1 > Author: Felix Fietkau <nbd@xxxxxxxx> > Date: Tue Aug 27 11:30:01 2024 +0200 > > wifi: mt76: mt7915: retry mcu messages > > In some cases MCU messages can get lost. Instead of failing completely, > attempt to recover by re-sending them. > > Link: https://patch.msgid.link/20240827093011.18621-14-nbd@xxxxxxxx > Signed-off-by: Felix Fietkau <nbd@xxxxxxxx> > > > In particular, skb_get() in mt76_mcu_skb_send_and_get_msg() is bumping skb users > refcount (making the skb shared) and pskb_expand_head() (run by __skb_grow() in > mt76s_tx_run_queue()) does not like shared skbs. > > @Felix: any input on it? Adding regressions list to Cc. -- https://patchwork.kernel.org/project/linux-wireless/list/ https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches