From patchwork Mon Aug 19 20:51:04 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Vasily Khoruzhick X-Patchwork-Id: 821899 Received: from mail-pl1-f177.google.com (mail-pl1-f177.google.com [209.85.214.177]) (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 CB68515E96 for ; Mon, 19 Aug 2024 20:51:43 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.214.177 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1724100705; cv=none; b=YWw92ceGQIkYCg0mB7SQ+3pEpw7v/y0KFzwiJMFCOoHU8ml9zhDriEXyzrQvHwplBcQLoZz3XlnUBLwddTYr/hohz4f3lPl+s5OaM2930lVc4x/Mc2PsXKc+u3sMRy9p79bzK8WYnw1i0rsZUZXPcdGd46H+QPtq1L8GLJvbJzE= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1724100705; c=relaxed/simple; bh=7papm/ncz5DtBVkXWxuPDjMAnp2JHZupr9tn5JLb3Q8=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=r0fSrplgCl/hDdkZOLLUvv+ZsEyOnZ2gMTZZhW3zhw080oQZ/RuxRzkbKb2gJYFj5heZg8X9XMgFGtzyf92gamxTdM7YPsQixDTrA+8bX/81FTDKKV3UasCQJDx/xqMcUzXJ/ib9sCAndLOSKmpXvWpRer//DNgDEwYljt4cWg4= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=arista.com; spf=pass smtp.mailfrom=arista.com; dkim=pass (2048-bit key) header.d=arista.com header.i=@arista.com header.b=T3YlUx+t; arc=none smtp.client-ip=209.85.214.177 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=arista.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arista.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=arista.com header.i=@arista.com header.b="T3YlUx+t" Received: by mail-pl1-f177.google.com with SMTP id d9443c01a7336-2021aeee5e4so13085285ad.0 for ; Mon, 19 Aug 2024 13:51:43 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=arista.com; s=google; t=1724100703; x=1724705503; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:from:to:cc:subject:date:message-id:reply-to; bh=2G0BlDQX2BP5LrBSVzTu3lq9EROMDDvEST6/TJJP3fo=; b=T3YlUx+tuPCHL3qTn968oTWGN5y3FpCXWamE5vCZLNpe4/7Q1n3vt9eLiBxwJ9/z8L s7ioC9L1Q2dwofq/JhjIWnsVHYWHlZqD/3QmzCebi2jTLJBR8Sr3CzsOuLE+cJB0OH5f dMxAeCMNTauRMWBWOD4v/enj7+5QEP0hxPObZMOWCWbdPj055jD5bX57+QtgXmIwaBAW jpvR9W9hlYjNJuyffC3TtmQVoNgka+PIiCG++xd55oj+Kl5ozDPHCrGeXcBEEuLzTxTl S7DCv6no9CL0F1hSuQ2d4fA8nicO59uJcPPts8kCjuP2/87PJilGPJaGPF/ta2LCYAnH fiWw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1724100703; x=1724705503; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=2G0BlDQX2BP5LrBSVzTu3lq9EROMDDvEST6/TJJP3fo=; b=cTBbWhNPD4xSwQsA0ZYbuLqwl3y/r7Mw57+WclkrJUspBvHUSZHYJnayDx/TFEiNEk 3cPczXrk8n+Murvh8sSR7SRS5gMeIqXtdCHvz4E1mtq6UTZtKUBRT0l30PJHAXysR32M RldhhR7GerAMOC6dolv1chLfqOlUYccNl5Sg1xHVtySdUq6fA/83HKOtJVl69NxtmjG2 eCIpxevacaN3iOXvk/exB2qo9T+852DTzt4xlp2gc+D2u0JsH6FtG3OKNylST5fYH8Io 7QK3QjeoxIYsqBqRJJAfwaUATr7EiF29akNqcvKhZDDt3UXcEWrzZMe3bNFgF+G/PFVA 0cdg== X-Forwarded-Encrypted: i=1; AJvYcCUfL3mh9SKjEsVM8RQhWH8RgS6Jp/YHiTAgoYrLSV9PLOCNc4lNdl+RZ9zEBv/81miQsgiYhTW1U+upUA1LgtrEYObOfXAG3UPZ X-Gm-Message-State: AOJu0YyMt0W4QjngwA5iOhZXx3/Ml6UFxmEM8qPMRf7asJGYkJehlOFL +JPiJ2I4ifMf+bMJ7TWecdbx/HgokJtya9DOozf/3ABeqOwmjyfXRHVDdQXQAA== X-Google-Smtp-Source: AGHT+IFrFHCSqWHcu4Z8LDTRZvobn1L1Rvr4vbhhohOOJ0K9ILHv9DA+m26gbXUkQGlIbbzwJ83AuA== X-Received: by 2002:a17:902:e84b:b0:202:18de:b419 with SMTP id d9443c01a7336-20218deb7a8mr88897145ad.63.1724100702925; Mon, 19 Aug 2024 13:51:42 -0700 (PDT) Received: from localhost.localdomain ([2604:3d08:7780:1ca9:d173:3faf:522f:33b9]) by smtp.gmail.com with ESMTPSA id d9443c01a7336-201f039ef11sm66606405ad.248.2024.08.19.13.51.41 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 19 Aug 2024 13:51:42 -0700 (PDT) From: Vasily Khoruzhick To: Seth Heasley , Neil Horman , Andi Shyti , linux-i2c@vger.kernel.org Cc: Vasily Khoruzhick Subject: [PATCH] i2c: ismt: kill transaction in hardware on timeout Date: Mon, 19 Aug 2024 13:51:04 -0700 Message-ID: <20240819205125.92358-1-vasilykh@arista.com> X-Mailer: git-send-email 2.45.2 Precedence: bulk X-Mailing-List: linux-i2c@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 On Intel Denverton SoC ismt controller may enter weird state when transaction gets stuck. It times out in the driver, but unless transaction is explicitly killed in the controller, it won't be able to perform new transactions anymore. The issue is extremely difficult to reproduce and may take weeks of non- stop smbus traffic. Numerous hours with logic analyzer didn't yield any useful results, it looks like the controller stops toggling SCK line, i.e. the issue is likely in the controller, since device doesn't do clock stretching, so nothing is driving SCK except the host. Explicitly kill transaction on timeout to recover the controller from this state. Signed-off-by: Vasily Khoruzhick --- drivers/i2c/busses/i2c-ismt.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/drivers/i2c/busses/i2c-ismt.c b/drivers/i2c/busses/i2c-ismt.c index 655b5d851c48..c93c02aa6ac8 100644 --- a/drivers/i2c/busses/i2c-ismt.c +++ b/drivers/i2c/busses/i2c-ismt.c @@ -381,6 +381,15 @@ static int ismt_process_desc(const struct ismt_desc *desc, return -EIO; } +/** + * ismt_kill_transaction() - kill current transaction + * @priv: iSMT private data + */ +static void ismt_kill_transaction(struct ismt_priv *priv) +{ + writel(ISMT_GCTRL_KILL, priv->smba + ISMT_GR_GCTRL); +} + /** * ismt_access() - process an SMBus command * @adap: the i2c host adapter @@ -623,6 +632,7 @@ static int ismt_access(struct i2c_adapter *adap, u16 addr, dma_unmap_single(dev, dma_addr, dma_size, dma_direction); if (unlikely(!time_left)) { + ismt_kill_transaction(priv); ret = -ETIMEDOUT; goto out; }