From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=91.218.175.3 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1794206584; b=Rf3CzanAfhITSu3xihIXpPIOWK0LyDHmZtOsVOplx8w9stgOook84B/WGsB2m5lxQ9cA wdPd5CB0cO42OtBiLuxdf0z+7HYnrHfg3FcusBvjrU9RyTWX6PJbO1PDqNovDskrrIjpb RAf1lZcpi/JbvPKxzZ1wIK79IPcuoQCWZsxcgjCQZsSqwz6zt+mTrXR7E5a2MSKi+6aG4 qqk7+Fj89Jo2s4RrePMTjxxqCsxH0tSg7K7FQgOchXU5Q9z6llJWJPI9+lUzCH6GfuaIA oWBK+Uh1/XZKFez+tyugX32ZGcyWIAGTZK5o3DS2ISYsdWV/fkihuwG0mXmpSDdRrIA== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794206584; h=DMARC-Filter:X-Envelope-To:DKIM-Signature:X-Envelope-To:Received: X-Mizu-Trace-ID:X-Migadu-Flow:Date:From:To:CC:Subject:In-Reply-To: References:Message-ID:MIME-Version:Content-Type: Content-Transfer-Encoding; bh=ebhEmtFiUyEh4cVX2pYWagxjHX97HdZXhWF4H/DoKjc=; b=jPXL38K0gMy6eM1IjSwQLkyIyn7UNjzCw8M7JINRtlod0d2DBvVjUAYKFpXetu+GP2vF zz5O9h2h0Y26xWDrW91/CpTUFKKceCvAG2gEASFYGh41xKSDe35+k0fDUgeCvckoxJODI lKFDuW/OH91179t2vG2W8jyeR9h34WT3tW94FiKrHCvy8sBjk59nMqqURD+heS0NUCh8N uI14h5rLoCIGTywMLDOj34dXEdksgzglfmz89NiXYgNPAOaYRiOfBN9ASAACr2VOu/VCM mqQHdJ4v+0vPHPmTzUPLuov+H8xHS0ncLZHtSM9LG2zPCKiuQqe2lR3qsJOtQNDn3/w== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass header.d=linux.dev header.i=@linux.dev header.a=rsa-sha256 header.s=key1 header.b=Yotv9l8c; arc=none smtp.remote-ip=91.218.175.3 Received: from mta0.migadu.com (out-3.mta0.migadu.com [91.218.175.3]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 139AB606A31C for ; Mon, 9 Nov 2026 06:43:03 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org 139AB606A31C Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key, unprotected) header.d=linux.dev header.i=@linux.dev header.a=rsa-sha256 header.s=key1 header.b=Yotv9l8c X-Envelope-To: linux-kernel@vger.kernel.org DKIM-Signature: a=rsa-sha256; bh=ebhEmtFiUyEh4cVX2pYWagxjHX97HdZXhWF4H/DoKjc=; c=simple/simple; d=linux.dev; h=from:to:subject:date:message-id:mime-version:content-type; s=key1; t=1794206582; v=1; x=1794811382; b=Yotv9l8c2RPenS6Q2Y3ubHJTNGrhHhL0KqXUB3FsjGLv9H+z4EwTKUr5x1lHauIQXR8SJxYp /RoSfgqYAHjbm6QqniwD8d9CSsNI4GpQHdqfYd87LT+FdU1xLAOQNg/5SO9MyGwc9CyNps+Tvu/ fnpcOVNvtniGJniKlb+9ma18= X-Envelope-To: linux-kernel@vger.kernel.org Received: by smtp.migadu.com with ESMTPS id 1563ae8dbb63b098; Mon, 09 Nov 2026 06:43:02 +0000 X-Mizu-Trace-ID: 1563ae8dbb63b098 X-Migadu-Flow: FLOW_OUT Date: Mon, 09 Nov 2026 07:43:00 +0100 From: Luka Gejak To: Zeshan Ahmed Nobin , linux-wireless@vger.kernel.org CC: linux-kernel@vger.kernel.org, Ping-Ke Shih , Kalle Valo Subject: =?US-ASCII?Q?Re=3A_=5BPATCH_RESEND_rtw-next_v2_2/2=5D_wifi=3A_rtw88=3A_?= =?US-ASCII?Q?8822c=3A_ignore_nrx_values_without_CCK_PD_registers?= In-Reply-To: <20261108182837.682661-3-zeshanahmednobin@gmail.com> References: <20261108182837.682661-1-zeshanahmednobin@gmail.com> <20261108182837.682661-3-zeshanahmednobin@gmail.com> Message-ID: <2C4EC68D-1844-4124-A40D-FD0BA0627A44@linux.dev> X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit On November 8, 2026 7:28:37 PM GMT+01:00, Zeshan Ahmed Nobin wrote: >rtw8822c_phy_cck_pd_set() reads nrx, the number of CCK RX paths minus >one, from a 2-bit register field. The driver only ever sets it to 0 or >1, for one or two RX paths (see rtw8822c_config_cck_rx_path()), and >rtw8822c_cck_pd_reg[] only has registers for those two values; its >entries for nrx 2 and 3 are all zero. > >A device that stops responding can return any value. On USB, a failed >read returns whatever an earlier read left in the buffer, so bw can be >0 or 1 while nrx is 2 or 3. When the level then changes, >rtw8822c_phy_cck_pd_set_reg() gets past its WARN_ON(), which only >checks nrx against RTW_RF_PATH_MAX, and calls rtw_read32_mask() and >rtw_write32_mask() on register 0x0 with a zero mask. Both compute >__ffs(0), which is undefined, and the write puts back whatever was read >from register 0x0. > >Return early when rtw8822c_cck_pd_reg[] has no registers for nrx; bw >has already been checked at that point. > >The fix and this message were drafted with an AI coding assistant >(Claude Opus 5.5 by Anthropic), then reviewed and tested by the >submitter. > >Reported-by: Luka Gejak >Closes: https://lore.kernel.org/linux-wireless/f6a7d3272fe7635c6a83698dfab5d85500437ca6@linux.dev/ >Fixes: 479c4ee931a6 ("rtw88: add dynamic cck pd mechanism") >Signed-off-by: Zeshan Ahmed Nobin >--- Looks good to me, Reviewed-by: Luka Gejak Best regards, Luka Gejak