From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793144988; b=pHXtV5ww0HHYRb4X2NXv7iHhW1gI+4oplbkjaubPtkaBoY+IGEVPV1iy8LNxsesYT5qE kAIve4M+ANViItYBbAbD51HewUm+ii7CQCW2x4nw4rYoSqIleEY5yWR1/BXAfswBxyM2H aSsSnJTwKxUF7YxJ6npaleUABhLJZ3jHn3I7eKtvVjy5G8qJarJ8gENQpjTT202SH5tT+ JBIFd8wv+rktjpHq1tOgiM9iZH+VRgELGYKxnatWz/ydpCbbNIjyBKFtoHgCBkbpCf2ZV /kcgle7zBUiyKSjEcGrrM3PilAnNJoXlIwAmkN6ekqYfmC8EZsY1TeTEOv6nK+1GS2w== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793144988; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:MIME-Version:Content-Transfer-Encoding; bh=OsGKoIGB8oJgiLBZispb/gUIEGCVQxTtM4o9rSDXfhw=; b=tc7rgqEJcqD+hjnhGAJiTtzo52eDzRfgq2fSqSvRR4HzLvNrjwUxHllESiTt2h6nOGM7 Xr0wEzmPFqcLaXYMPF6SyOs6g/5J4pV1omGGpNeOp91Dez+IHV4KH3+UV2p57UTE1koPx LI0zcQ+vF/NgN3C96OVNKNd2ZDc3p4NE3GOebdxowL3xmaUwPm/8RIrQyFdw3KIjuOaTh BOXZ4lW8beOnpxNFCni+cE7Gu4sX3eGhNcxuix+OXSsfTCfeg1BxmibGI21z9puUti5Um 7U5EWceNFdIoTh73qtakAUJtev03gcnbNxydiNQ58kse+6YrQZFimrwwC3o6GRoAnSQ== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b="MTfEj/DO"; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 9A2A6606A326 for ; Tue, 27 Oct 2026 23:49:48 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=MTfEj/DO Received: by smtp.kernel.org (Postfix) with ESMTPSA id BD5041F031E3; Tue, 27 Oct 2026 23:49:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1793144988; bh=OsGKoIGB8oJgiLBZispb/gUIEGCVQxTtM4o9rSDXfhw=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=MTfEj/DOaBV7UYVHeUcCXXbeOORi8rcuarCC7lAfzfkNg9g545SEA7YTD6k8Ia01y qHYk1Ou7bWBQAYbexg9LykKfmicFsawznISakqXhLqM2eQjA+S7fNXxNZF0dmFDYCe QNLry+IJZ6nOFmBCI4twxjvHJAoW2ioQSWYykebmRqMDr6RctHDr3r4tw95UycBzkw v426Tld9CcRlrVdymC7KOk3dbg04ObeoK9cScagjqmVJQkNbdyoQmfqf1vxYX9Seok Dcb/iB1fEBDV/LLJpt6R934Z75Ol3RyHqBwmTXGMBsOD1FAho+YBkw4zkIolFR31Ip A+f0bmhEP5F8Q== From: Jakub Kicinski To: davem@davemloft.net Cc: netdev@vger.kernel.org, edumazet@google.com, pabeni@redhat.com, andrew+netdev@lunn.ch, horms@kernel.org, michael.chan@broadcom.com, pavan.chebbi@broadcom.com, hawk@kernel.org, john.fastabend@gmail.com, sdf@fomichev.me, eddie.wai@broadcom.com, prashant@broadcom.com, huangjw@broadcom.com, gospo@broadcom.com, brett.creeley@amd.com, ap420073@gmail.com, joe@dama.to, Jakub Kicinski Subject: [PATCH net 2/5] eth: bnxt: resize Rx head buffers when rx-copybreak changes Date: Tue, 27 Oct 2026 16:49:37 -0700 Message-ID: <20261027234940.1267225-3-kuba@kernel.org> X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261027234940.1267225-1-kuba@kernel.org> References: <20261027234940.1267225-1-kuba@kernel.org> X-Mailing-List: netdev@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Since rx-copybreak became configurable, bnxt_set_ring_params() sizes the head buffers to fit at least rx_copybreak bytes, and the copybreak path in bnxt_copy_data() syncs rx_copybreak bytes of the head buffer. bnxt_set_tunable() however only updates bp->rx_copybreak, and nothing on the open path recalculates the ring parameters. After raising rx-copybreak the head buffers keep their old size until some other setting changes, and bnxt_copy_data() syncs past their end, into the next buffer in the page or past the end of the page: DMA-API: bnxt_en 0000:01:00.0: device driver tries to sync DMA memory it has not allocated [device address=0x00000002aa210c40] [size=1024 bytes] WARNING: kernel/dma/debug.c:1162 at check_sync+0x577/0x1eb0, CPU#22: swapper/22/0 Call Trace: debug_dma_sync_single_for_cpu+0x66/0x90 bnxt_copy_data+0x12f/0x290 bnxt_rx_pkt+0x24ea/0x50f0 __bnxt_poll_work+0x42c/0xc00 bnxt_poll_p5+0x579/0x17a0 __napi_poll+0x8b/0x2c0 net_rx_action+0x58f/0xbb0 Here the head buffers were still sized for the 640B HDS threshold, four 1kB buffers per page, while rx-copybreak was raised to 1024. Without coherent DMA or with swiotlb the oversized sync can corrupt a neighboring buffer owned by the device or by an skb. The device must be down for rx-copybreak to change, so recalculate the ring parameters right away, like bnxt_set_ringparam() does. Hit while testing patch 1, tested on BCM57504 - boot; set rx-copybreak to 1024 with the link down (CONFIG_DMA_API_DEBUG); ifup. Fixes: 152f4da05aee ("bnxt_en: add support for rx-copybreak ethtool command") Signed-off-by: Jakub Kicinski --- drivers/net/ethernet/broadcom/bnxt/bnxt_ethtool.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt_ethtool.c b/drivers/net/ethernet/broadcom/bnxt/bnxt_ethtool.c index 622e89587e5d..ef4bea4a0f8c 100644 --- a/drivers/net/ethernet/broadcom/bnxt/bnxt_ethtool.c +++ b/drivers/net/ethernet/broadcom/bnxt/bnxt_ethtool.c @@ -4601,6 +4601,7 @@ static int bnxt_set_tunable(struct net_device *dev, if (netif_running(dev)) return -EBUSY; bp->rx_copybreak = rx_copybreak; + bnxt_set_ring_params(bp); } return 0; case ETHTOOL_PFC_PREVENTION_TOUT: -- 2.56.0