From patchwork Tue Sep 10 11:16:51 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Michal Pecio X-Patchwork-Id: 827306 Received: from mail-ej1-f49.google.com (mail-ej1-f49.google.com [209.85.218.49]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 2802B14D280 for ; Tue, 10 Sep 2024 11:16:56 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.218.49 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1725967018; cv=none; b=paXOtRdfVg62haWiLkpfm68izlYwifBusXMM1/6y9TMzEAw0tLHBgdL9Imlruju0S/YX1HomEn2ZRym4KtcKbE1JfeGHAlz6Z3viqnpqiFijbMqt7OEsaW76sBb8HRH5Nzc/8JvBBdcThxO37DlrH7Cmsd2I5AKS7HEfgyo+fRs= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1725967018; c=relaxed/simple; bh=RzA8ZfBNebEsL0U5EB0QNzsHYZZILFS9ayPAuMzNedU=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=JNOZzVLbQfcmyaNZ/clIixP21ALCI673BDP2w+sY8ts9nGPawfH7e/89OOnEorB+qXKGmo+GVUGPboxpWWhPN9eiY569k1sUUeTI37BhJXrksWxDL7fQq33Sm/dW4ne6Y3bpejr9W5EaLz8sUI/XZRvEknC4QEwSwu6DXBwNMPk= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=BlcVisH+; arc=none smtp.client-ip=209.85.218.49 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="BlcVisH+" Received: by mail-ej1-f49.google.com with SMTP id a640c23a62f3a-a8d2b24b7a8so515618066b.1 for ; Tue, 10 Sep 2024 04:16:56 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1725967015; x=1726571815; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:subject:cc:to:from:date:from:to:cc:subject:date :message-id:reply-to; bh=NgX0n39MutN0cvoOhVPaaxt+3vWBflrma3+4LJoEaP8=; b=BlcVisH+ZRVtET0jlCK54rDjOWlgE5jDwcbJMqZqOc6KFAN9eHdrxM28uzQ3RoAuQ1 UCc6bVQ56Qy7MXkWSWffycexvHS6EBx/sKQnlwmC4v3TFQjN7KmnILQGk8DPIjSBGhlS fojOQZDYTYmHUw2yba09BTO9sNC+6gNzwaWh/XiPsQhPZY+Uq/4N13JYxB3y13il369V 4yGm+o+HoRWThxy5kQczWRk1gExJFa9nnJ/PrIcKxxjYOGgtPd+KP5k9x/CPclHD4vo8 3N0n/ynH5O38c9HBeQoz7VcWr/veqNZ06OGEYYPLc7gGXC9b3AscJXbfLoKmdg7qOezI y5cQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1725967015; x=1726571815; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:subject:cc:to:from:date:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=NgX0n39MutN0cvoOhVPaaxt+3vWBflrma3+4LJoEaP8=; b=NseWlMeBGWEcQjCWd0U2oNRv8wqQ7Xka396S/9v2zveJEiCFBD/NG+mRLWfzzizQq3 Ahnh3vVlcZLIFQxydo+pD6GzadZjwbMQHCizFjxS0AHel0p5u+ny0bfMRhbNT8Q6lJYk vZ0vW147FeQtAQTB6cvM+3xGoWQ3Q/yH7Pvmm7mhGk4F+YBb3Vb15yJgX9/C6EScYFGY uNJHUusjcF4/BRWeg6kV20jjCVGPqcoDGh/l/2JSBtx4sA9syq3QKc2qTSTaxxFWAe7q CSHTy7iCV4mmyPTdsAD7cxe6UtC55It8E7A2UX7eRhi+45SeRaux99t2vT1GOiTMe5fP ZJCw== X-Gm-Message-State: AOJu0Yzqlsd7MzTBZQ5grYAf52gNIEJjKwVxmGdWeeVbLv3WAzOEGlJI DJpcrTh3uu1zcueOjVmd61HV2jOgn8Yz5ShwU3KQcIJf0S7YfDgW X-Google-Smtp-Source: AGHT+IHhRZv8aH73spqLvaZpwaWLYgowTlUvPB3ENhkpsThbDaDF6Eti15Lz4Yo/uUuW+cDQi+o6yw== X-Received: by 2002:a17:907:6d09:b0:a7a:8284:c8d6 with SMTP id a640c23a62f3a-a8ffb29987emr38307166b.24.1725967014954; Tue, 10 Sep 2024 04:16:54 -0700 (PDT) Received: from foxbook (bgv123.neoplus.adsl.tpnet.pl. [83.28.85.123]) by smtp.gmail.com with ESMTPSA id a640c23a62f3a-a8d25951020sm468382966b.66.2024.09.10.04.16.54 (version=TLS1_2 cipher=AES128-SHA bits=128/128); Tue, 10 Sep 2024 04:16:54 -0700 (PDT) Date: Tue, 10 Sep 2024 13:16:51 +0200 From: Michal Pecio To: Mathias Nyman , Niklas Neronin Cc: linux-usb@vger.kernel.org Subject: [PATCH 5/5] usb: xhci: Fix Ring Underrun/Overrun handling Message-ID: <20240910131651.6c4c0195@foxbook> In-Reply-To: <20240910131233.409c6481@foxbook> References: <20240910131233.409c6481@foxbook> Precedence: bulk X-Mailing-List: linux-usb@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Depending on implemented spec revision, the TRB pointer of these events may either be NULL or point at enqueue at the time of error occurrence. By the time we handle the event, a new TD may be queued at this address. Ensure that the new TD is not completed prematurely if the event handler is entered due to the skip flag being set on the endpoint. Or, when the TRB pointer is NULL, prevent the empty ring warning being printed. Now that it is safe to enter the event handler, also enter it when the skip flag is not set. This enables completion of any TD stuck in 'error mid TD' state on buggy hosts. Such problem could, for example, happen when a USBFS application knows in advance how many frames it needs and submits the exact number of URBs, then an error occurs on the last TD. One bug remains: when enqueue points at a Link TRB and a new TD appears after that, skipping will remove the new TD prematurely. This should be 255 times less common that the 'matching TD' bug being fixed here, and it will take a major improvement to the skipping loop to fix. Signed-off-by: Michal Pecio --- drivers/usb/host/xhci-ring.c | 17 +++++++++++------ 1 file changed, 11 insertions(+), 6 deletions(-) diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c index db9bc7db5aac..475b4d69551b 100644 --- a/drivers/usb/host/xhci-ring.c +++ b/drivers/usb/host/xhci-ring.c @@ -2726,14 +2726,10 @@ static int handle_tx_event(struct xhci_hcd *xhci, * Underrun Event for OUT Isoch endpoint. */ xhci_dbg(xhci, "Underrun event on slot %u ep %u\n", slot_id, ep_index); - if (ep->skip) - break; - return 0; + break; case COMP_RING_OVERRUN: xhci_dbg(xhci, "Overrun event on slot %u ep %u\n", slot_id, ep_index); - if (ep->skip) - break; - return 0; + break; case COMP_MISSED_SERVICE_ERROR: /* * When encounter missed service error, one or more isoc tds @@ -2824,6 +2820,15 @@ static int handle_tx_event(struct xhci_hcd *xhci, skipped, td ? "":"not ", slot_id, ep_index); } + /* + * In these events ep_trb_dma is NULL or points at enqueue from the time + * of error occurrence. If it matches a new TD queued since then, don't + * complete the TD now. And otherwise, don't print senseless warnings. + */ + if (trb_comp_code == COMP_RING_UNDERRUN || + trb_comp_code == COMP_RING_OVERRUN) + return 0; + if (!ep_seg) { /*