From patchwork Sat Feb 8 03:31:29 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Badhri Jagan Sridharan X-Patchwork-Id: 863548 Received: from mail-pj1-f74.google.com (mail-pj1-f74.google.com [209.85.216.74]) (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 4B39C611E for ; Sat, 8 Feb 2025 03:31:33 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.216.74 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1738985494; cv=none; b=JXwRa0GbM3Le5pBTK+EXeGGJ0V8SD9Q/+6VDhvIwhOdtWdgR/sIN8tBgT+bqqlebtXxk6g3bUhRGdMkeroLR5ncTFqub279A1QnoAzC3UI04CgtDlcd4uZwRGpeAZnL/7k1a1pCU/Ty4S5qw4AqSBnS+qQxHLfqBP3oCYTkEvMQ= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1738985494; c=relaxed/simple; bh=+sardm/LolQw6ziPvWfFf1wd1dVDkIErwNJaVuBhKCI=; h=Date:Mime-Version:Message-ID:Subject:From:To:Cc:Content-Type; b=FPBb3jHieIv12nXuQ9uJIrQm9MVppJPTb4x8t7/+570i43LXMvxJEu07YHvRto41KUmTeL2EOkdg2PPssFfTccY2BY9BE6SUJZ+3fjCfU9WKaHAmT//9kuRMZg0Nv1tTHutp/uzh9NxIgZyOro9Qm4hapg63wA7bB315KxGNwfM= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--badhri.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=LJFz7KrD; arc=none smtp.client-ip=209.85.216.74 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--badhri.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="LJFz7KrD" Received: by mail-pj1-f74.google.com with SMTP id 98e67ed59e1d1-2fa44233a04so724612a91.1 for ; Fri, 07 Feb 2025 19:31:33 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1738985492; x=1739590292; darn=vger.kernel.org; h=cc:to:from:subject:message-id:mime-version:date:from:to:cc:subject :date:message-id:reply-to; bh=p0gZ2q9HM3rX07kpmvYyR39VyXsdRnL4CUz3gU+Woqc=; b=LJFz7KrDHsIKgE1KF5CTCVOYMs+coq4m0/ipl0e6pW7LQ5n6CX5+40/KgcCubxkXm3 o94Q9oPCMQYLHH3a9NPJ1hTK6ZxI1wQIyavXF3Fv8LQxJGlwLwaBV9p7bgxfYS9kTeI9 s14fgdWz8kX9U6R7cYZenisjEB/wRDRODQ5CCgeJUPGxpCqtuPirEo4n51djQcK8UEtb IFiT4Zk3vbUW39kEGzWFR9pov6wBVCNcqMqesMC1VRNo2VQV6ixvvUpOH0929BVuFMR6 52os5NztoupKNjWx3tpVkD1xezoWWz3zou9zgCdxl4cT1AhCPHvJgmBnlamDUrpNwR8S kvMA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1738985492; x=1739590292; h=cc:to:from:subject:message-id:mime-version:date:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=p0gZ2q9HM3rX07kpmvYyR39VyXsdRnL4CUz3gU+Woqc=; b=c4rkLaOvO69Hxf/nMJ74JGdXFRMaLIKB+cKP1rAymAqp3z/gj919CmSFdBsalGgZBb 9mPj4jUgMpSUGLMt+LXW2g+u9fR7QNqjH8uV2hyyDvBveD0KDQhvuXdlnj4fIgYIhPDS WKgpolxRis4Ck0a+rg9h+hG4vLCXMOWrqlBL0GBsb5IQqBH0o5jEIJ5yIqXhJqddrsN7 68kjUKJhfoDEQM3q6jjcEvMKs8GSSIfPiP3g7uz8YpfH8/MriBJy8LTwecrXod3V++Q4 uw8tZUZFPvnPjEX3tEzBB7D4w1sofrGc2Ipmd6XqLRQXXKnqy9zQ/sqU2vLMB2iRnQ2u kpFA== X-Gm-Message-State: AOJu0YzEzzZDXEFZNfzGX3tc6DQJM/urJk3iTOBV7PKQLBOAzXmFZdj0 VvSg6NkDYFePoXguAHKlrqsUK/zhsmYW4JtlguDyOmbdbbPD5CQyUulVsoxccY82SW2MelsLiM7 ePg== X-Google-Smtp-Source: AGHT+IHF6JQH1xgZnqdPNtMVklKecXq5Aajik4oseZpvmg90/Ega/bv/OBxCXP5JoMVF9e7hXVZw8+bCgNQ= X-Received: from pjbsp15.prod.google.com ([2002:a17:90b:52cf:b0:2ee:53fe:d0fc]) (user=badhri job=prod-delivery.src-stubby-dispatcher) by 2002:a17:90b:2d8c:b0:2f9:9ddd:689b with SMTP id 98e67ed59e1d1-2fa242e75eamr7097462a91.22.1738985492599; Fri, 07 Feb 2025 19:31:32 -0800 (PST) Date: Sat, 8 Feb 2025 03:31:29 +0000 Precedence: bulk X-Mailing-List: linux-usb@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 X-Mailer: git-send-email 2.48.1.502.g6dc24dfdaf-goog Message-ID: <20250208033129.3524423-1-badhri@google.com> Subject: [PATCH v2] usb: dwc3: gadget: Prevent irq storm when TH re-executes From: Badhri Jagan Sridharan To: Thinh.Nguyen@synopsys.com, gregkh@linuxfoundation.org, felipe.balbi@linux.intel.com Cc: linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, jameswei@google.com, Badhri Jagan Sridharan , stable@kernel.org 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 clearing 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@kernel.org Suggested-by: Thinh Nguyen Fixes: d325a1de49d6 ("usb: dwc3: gadget: Prevent losing events in event cache") Signed-off-by: Badhri Jagan Sridharan --- drivers/usb/dwc3/core.c | 2 +- drivers/usb/dwc3/gadget.c | 10 +++++++--- 2 files changed, 8 insertions(+), 4 deletions(-) base-commit: 9682c35ff6ecd76d9462d4749b8b413d3e8e605e diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c index dfa1b5fe48dc..6df971ef7285 100644 --- a/drivers/usb/dwc3/core.c +++ b/drivers/usb/dwc3/core.c @@ -1835,7 +1835,7 @@ static void dwc3_get_properties(struct dwc3 *dwc) 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->imod_interval = 1; dwc->tx_fifo_resize_max_num = tx_fifo_resize_max_num; } diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c index d27af65eb08a..fad115113d28 100644 --- a/drivers/usb/dwc3/gadget.c +++ b/drivers/usb/dwc3/gadget.c @@ -4467,14 +4467,18 @@ static irqreturn_t dwc3_process_event_buf(struct dwc3_event_buffer *evt) 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; }