From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 B9EA32309B0; Mon, 10 Mar 2025 17:15:37 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741626937; cv=none; b=pv8SVhWS+jRP6iyj/xllJ1koEY6O9EYqMueNYj/c9KqlQJf2W0zexlNhxFoIX5OV+q17d5oyWo2+r9RO4CbrOyrMPkV5thnHCO8BGdg2BTM/FXyKmbm0RvXOhtVHABfT5nxjkiS1CexG9iwveuVSH8Rbrf6z8MEfRVHZTb5LTJI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741626937; c=relaxed/simple; bh=XUnrfdkQeQLHj8OjOexmylujSq50nVd/SpS0blH0MXg=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=d81ClDqFyMCaztZDU76ZPqem/1qIoKFDgjKBN1fH4Czi1qpb2Jym8D8zIBBExYsebu6KccXZpcKtZnxt0/SMioOmjxAIw8zTXS1vqLfRR1Utz/WNoD4Q+6qaRM6agjih0rPGcXDQdKmujBcSXMq5eZuLeIk1V3GPV18uonVYjGo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=1ffy21xW; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="1ffy21xW" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 437A0C4CEE5; Mon, 10 Mar 2025 17:15:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1741626937; bh=XUnrfdkQeQLHj8OjOexmylujSq50nVd/SpS0blH0MXg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=1ffy21xWwnP2VMfTn7itFg4WiSpIG9vw6RvzsD87a96S2lfGuNb2BQVeTs7hSTMHU NEY66eeWcPSBOvLqshLsuhqVyoDNduEofa7q9kM8vku+/LCYiXjGIdc10a0hu81K8t 9Y7onN/OLylVro7La4t189ZJ+d33rQJLxx8xL0L4= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, stable , Thinh Nguyen , Badhri Jagan Sridharan Subject: [PATCH 6.13 164/207] usb: dwc3: gadget: Prevent irq storm when TH re-executes Date: Mon, 10 Mar 2025 18:05:57 +0100 Message-ID: <20250310170454.307429624@linuxfoundation.org> X-Mailer: git-send-email 2.48.1 In-Reply-To: <20250310170447.729440535@linuxfoundation.org> References: <20250310170447.729440535@linuxfoundation.org> User-Agent: quilt/0.68 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.13-stable review patch. If anyone has any objections, please let me know. ------------------ From: Badhri Jagan Sridharan commit 69c58deec19628c8a686030102176484eb94fed4 upstream. While commit d325a1de49d6 ("usb: dwc3: gadget: Prevent losing events in event cache") makes sure that top half(TH) does not end up overwriting the cached events before processing them when the TH gets invoked more than one time, returning IRQ_HANDLED results in occasional irq storm where the TH hogs the CPU. The irq storm can be prevented by the flag before event handler busy is cleared. Default enable interrupt moderation in all versions which support them. ftrace event stub during dwc3 irq storm: irq/504_dwc3-1111 ( 1111) [000] .... 70.000866: irq_handler_exit: irq=14 ret=handled irq/504_dwc3-1111 ( 1111) [000] .... 70.000872: irq_handler_entry: irq=504 name=dwc3 irq/504_dwc3-1111 ( 1111) [000] .... 70.000874: irq_handler_exit: irq=504 ret=handled irq/504_dwc3-1111 ( 1111) [000] .... 70.000881: irq_handler_entry: irq=504 name=dwc3 irq/504_dwc3-1111 ( 1111) [000] .... 70.000883: irq_handler_exit: irq=504 ret=handled irq/504_dwc3-1111 ( 1111) [000] .... 70.000889: irq_handler_entry: irq=504 name=dwc3 irq/504_dwc3-1111 ( 1111) [000] .... 70.000892: irq_handler_exit: irq=504 ret=handled irq/504_dwc3-1111 ( 1111) [000] .... 70.000898: irq_handler_entry: irq=504 name=dwc3 irq/504_dwc3-1111 ( 1111) [000] .... 70.000901: irq_handler_exit: irq=504 ret=handled irq/504_dwc3-1111 ( 1111) [000] .... 70.000907: irq_handler_entry: irq=504 name=dwc3 irq/504_dwc3-1111 ( 1111) [000] .... 70.000909: irq_handler_exit: irq=504 ret=handled irq/504_dwc3-1111 ( 1111) [000] .... 70.000915: irq_handler_entry: irq=504 name=dwc3 irq/504_dwc3-1111 ( 1111) [000] .... 70.000918: irq_handler_exit: irq=504 ret=handled irq/504_dwc3-1111 ( 1111) [000] .... 70.000924: irq_handler_entry: irq=504 name=dwc3 irq/504_dwc3-1111 ( 1111) [000] .... 70.000927: irq_handler_exit: irq=504 ret=handled irq/504_dwc3-1111 ( 1111) [000] .... 70.000933: irq_handler_entry: irq=504 name=dwc3 irq/504_dwc3-1111 ( 1111) [000] .... 70.000935: irq_handler_exit: irq=504 ret=handled .... Cc: stable Suggested-by: Thinh Nguyen Fixes: d325a1de49d6 ("usb: dwc3: gadget: Prevent losing events in event cache") Signed-off-by: Badhri Jagan Sridharan Acked-by: Thinh Nguyen Link: https://lore.kernel.org/r/20250216223003.3568039-1-badhri@google.com Signed-off-by: Greg Kroah-Hartman --- drivers/usb/dwc3/core.c | 16 ++++++---------- drivers/usb/dwc3/gadget.c | 10 +++++++--- 2 files changed, 13 insertions(+), 13 deletions(-) --- a/drivers/usb/dwc3/core.c +++ b/drivers/usb/dwc3/core.c @@ -1830,8 +1830,6 @@ static void dwc3_get_properties(struct d dwc->tx_thr_num_pkt_prd = tx_thr_num_pkt_prd; dwc->tx_max_burst_prd = tx_max_burst_prd; - dwc->imod_interval = 0; - dwc->tx_fifo_resize_max_num = tx_fifo_resize_max_num; } @@ -1849,21 +1847,19 @@ static void dwc3_check_params(struct dwc unsigned int hwparam_gen = DWC3_GHWPARAMS3_SSPHY_IFC(dwc->hwparams.hwparams3); - /* Check for proper value of imod_interval */ - if (dwc->imod_interval && !dwc3_has_imod(dwc)) { - dev_warn(dwc->dev, "Interrupt moderation not supported\n"); - dwc->imod_interval = 0; - } - /* + * Enable IMOD for all supporting controllers. + * + * Particularly, DWC_usb3 v3.00a must enable this feature for + * the following reason: + * * Workaround for STAR 9000961433 which affects only version * 3.00a of the DWC_usb3 core. This prevents the controller * interrupt from being masked while handling events. IMOD * allows us to work around this issue. Enable it for the * affected version. */ - if (!dwc->imod_interval && - DWC3_VER_IS(DWC3, 300A)) + if (dwc3_has_imod((dwc))) dwc->imod_interval = 1; /* Check the maximum_speed parameter */ --- a/drivers/usb/dwc3/gadget.c +++ b/drivers/usb/dwc3/gadget.c @@ -4494,14 +4494,18 @@ static irqreturn_t dwc3_process_event_bu dwc3_writel(dwc->regs, DWC3_GEVNTSIZ(0), DWC3_GEVNTSIZ_SIZE(evt->length)); + evt->flags &= ~DWC3_EVENT_PENDING; + /* + * Add an explicit write memory barrier to make sure that the update of + * clearing DWC3_EVENT_PENDING is observed in dwc3_check_event_buf() + */ + wmb(); + if (dwc->imod_interval) { dwc3_writel(dwc->regs, DWC3_GEVNTCOUNT(0), DWC3_GEVNTCOUNT_EHB); dwc3_writel(dwc->regs, DWC3_DEV_IMOD(0), dwc->imod_interval); } - /* Keep the clearing of DWC3_EVENT_PENDING at the end */ - evt->flags &= ~DWC3_EVENT_PENDING; - return ret; }