From nobody Sun Feb 8 12:03:29 2026 Received: from mailout2.samsung.com (mailout2.samsung.com [203.254.224.25]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 32C6F2BDC1D for ; Mon, 17 Nov 2025 16:01:01 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=203.254.224.25 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1763395264; cv=none; b=B6mHmeT+GW2TNRfQlr6Ceo0CjSjmVXqhpySgWcCLcnq3xZo/IVailrF/NLamPbu2E0W+PUzs0zbLXRxi0QqoSI10DH50DX47WSt3LJLLAE7mnJ2/HUzzB1/HTrpUEyrDjpGLkAzA0MO1/adwd4nbYyIrlSrci7arrZxje3ZKwZs= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1763395264; c=relaxed/simple; bh=9RSsR5U4W7BTG6LYCPzyJndp7H3oEE0mKDMWjHJa7qM=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version:Content-Type: References; b=FAVsSnWg0TgiPXEhRCfk0vw23jwiGRU8/6OktPEL9LdydjtJ0P1/bdAt850+G2OS1kLcKBq+gvH4nTS31Kqg26dQXYO/kFzXf0CwYOpNfLOUV/zjJ8nLMR0XsgyNo2GiXV/IuVz9mrc0PQ3OfPi/4t859/L3hYpsD792xhR130A= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=samsung.com; spf=pass smtp.mailfrom=samsung.com; dkim=pass (1024-bit key) header.d=samsung.com header.i=@samsung.com header.b=VpB8Qkkl; arc=none smtp.client-ip=203.254.224.25 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=samsung.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=samsung.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=samsung.com header.i=@samsung.com header.b="VpB8Qkkl" Received: from epcas5p1.samsung.com (unknown [182.195.41.39]) by mailout2.samsung.com (KnoxPortal) with ESMTP id 20251117160059epoutp028e1837d69d86d826f0947426ff3e607f~41qU6Noeg2393523935epoutp02p for ; Mon, 17 Nov 2025 16:00:59 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 mailout2.samsung.com 20251117160059epoutp028e1837d69d86d826f0947426ff3e607f~41qU6Noeg2393523935epoutp02p DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=samsung.com; s=mail20170921; t=1763395259; bh=I67VOD55Qfnuqg41UpFlurJxMf6XJBCy6vb0p2590/c=; h=From:To:Cc:Subject:Date:References:From; b=VpB8Qkklg7Y5B2IP/Eg3coJvDNgEdKAI7mtdUnWOV6ceQ0jDZ7w8YLxmTEPusAvK1 oXkrXZ12mPKDqJBUxNTLhOdmOFUUPMYJN8QoLsoiJtiM0tg32BPCihphDDe4FU/Zu5 FU1PwQDkLUQrG4m37wqQRT6+XZJRwRAXKT7uM9G0= Received: from epsnrtp04.localdomain (unknown [182.195.42.156]) by epcas5p4.samsung.com (KnoxPortal) with ESMTPS id 20251117160058epcas5p4719f72c4469d4e16f94ca8356b35d72a~41qUZD3Sp2883528835epcas5p4j; Mon, 17 Nov 2025 16:00:58 +0000 (GMT) Received: from epcas5p4.samsung.com (unknown [182.195.38.94]) by epsnrtp04.localdomain (Postfix) with ESMTP id 4d9CCF51Ndz6B9m6; Mon, 17 Nov 2025 16:00:57 +0000 (GMT) Received: from epsmtip1.samsung.com (unknown [182.195.34.30]) by epcas5p3.samsung.com (KnoxPortal) with ESMTPA id 20251117160057epcas5p324eddf1866146216495186a50bcd3c01~41qS3iGLm2061120611epcas5p3J; Mon, 17 Nov 2025 16:00:57 +0000 (GMT) Received: from INBRO002811.samsungds.net (unknown [107.122.5.126]) by epsmtip1.samsung.com (KnoxPortal) with ESMTPA id 20251117160055epsmtip1f7d3368895afa49a595ca513148de7b8~41qRBUXrh0499104991epsmtip1K; Mon, 17 Nov 2025 16:00:54 +0000 (GMT) From: Selvarasu Ganesan To: Thinh.Nguyen@synopsys.com, gregkh@linuxfoundation.org, linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org Cc: jh0801.jung@samsung.com, dh10.jung@samsung.com, naushad@samsung.com, akash.m5@samsung.com, h10.kim@samsung.com, eomji.oh@samsung.com, alim.akhtar@samsung.com, thiagu.r@samsung.com, Selvarasu Ganesan , stable@vger.kernel.org Subject: [PATCH v2] usb: dwc3: gadget: Prevent EPs resource conflict during StartTransfer Date: Mon, 17 Nov 2025 21:29:13 +0530 Message-ID: <20251117155920.643-1-selvarasu.g@samsung.com> X-Mailer: git-send-email 2.46.0.windows.1 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-CMS-MailID: 20251117160057epcas5p324eddf1866146216495186a50bcd3c01 X-Msg-Generator: CA Content-Type: text/plain; charset="utf-8" CMS-TYPE: 105P cpgsPolicy: CPGSC10-542,Y X-CFilter-Loop: Reflected X-CMS-RootMailID: 20251117160057epcas5p324eddf1866146216495186a50bcd3c01 References: The below =E2=80=9CNo resource for ep=E2=80=9D warning appears when a Start= Transfer command is issued for bulk or interrupt endpoints in `dwc3_gadget_ep_enable` while a previous StartTransfer on the same endpoint is still in progress. The gadget functions drivers can invoke `usb_ep_enable` (which triggers a new StartTransfer command) before the earlier transfer has completed. Because the previous StartTransfer is still active, `dwc3_gadget_ep_disable` can skip the required `EndTransfer` due to `DWC3_EP_DELAY_STOP`, leading to the endpoint resources are busy for previous StartTransfer and warning ("No resource for ep") from dwc3 driver. To resolve this, a check is added to `dwc3_gadget_ep_enable` that checks the `DWC3_EP_TRANSFER_STARTED` flag before issuing a new StartTransfer. By preventing a second StartTransfer on an already busy endpoint, the resource conflict is eliminated, the warning disappears, and potential kernel panics caused by `panic_on_warn` are avoided. ------------[ cut here ]------------ dwc3 13200000.dwc3: No resource for ep1out WARNING: CPU: 0 PID: 700 at drivers/usb/dwc3/gadget.c:398 dwc3_send_gadget_= ep_cmd+0x2f8/0x76c Call trace: dwc3_send_gadget_ep_cmd+0x2f8/0x76c __dwc3_gadget_ep_enable+0x490/0x7c0 dwc3_gadget_ep_enable+0x6c/0xe4 usb_ep_enable+0x5c/0x15c mp_eth_stop+0xd4/0x11c __dev_close_many+0x160/0x1c8 __dev_change_flags+0xfc/0x220 dev_change_flags+0x24/0x70 devinet_ioctl+0x434/0x524 inet_ioctl+0xa8/0x224 sock_do_ioctl+0x74/0x128 sock_ioctl+0x3bc/0x468 __arm64_sys_ioctl+0xa8/0xe4 invoke_syscall+0x58/0x10c el0_svc_common+0xa8/0xdc do_el0_svc+0x1c/0x28 el0_svc+0x38/0x88 el0t_64_sync_handler+0x70/0xbc el0t_64_sync+0x1a8/0x1ac Fixes: a97ea994605e ("usb: dwc3: gadget: offset Start Transfer latency for = bulk EPs") Cc: stable@vger.kernel.org Signed-off-by: Selvarasu Ganesan --- Changes in v2: - Removed change-id. - Updated commit message. Link to v1: https://lore.kernel.org/linux-usb/20251117152812.622-1-selvaras= u.g@samsung.com/ --- drivers/usb/dwc3/gadget.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c index 1f67fb6aead5..8d3caa71ea12 100644 --- a/drivers/usb/dwc3/gadget.c +++ b/drivers/usb/dwc3/gadget.c @@ -963,8 +963,9 @@ static int __dwc3_gadget_ep_enable(struct dwc3_ep *dep,= unsigned int action) * Issue StartTransfer here with no-op TRB so we can always rely on No * Response Update Transfer command. */ - if (usb_endpoint_xfer_bulk(desc) || - usb_endpoint_xfer_int(desc)) { + if ((usb_endpoint_xfer_bulk(desc) || + usb_endpoint_xfer_int(desc)) && + !(dep->flags & DWC3_EP_TRANSFER_STARTED)) { struct dwc3_gadget_ep_cmd_params params; struct dwc3_trb *trb; dma_addr_t trb_dma; --=20 2.34.1