From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mx0b-0031df01.pphosted.com (mx0b-0031df01.pphosted.com [205.220.180.131]) (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 BB3AB2931CE for ; Wed, 15 Jul 2026 07:31:13 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=205.220.180.131 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784100677; cv=none; b=CJN6FOOsSBuswqHnxLsO6i/FcYW1vxPLubhPbJJouv03QFy7S0LYQ7HL1pjGhYvyXY7mR8VYpRK0tyU3csEmlcBiE9IpMDlsnZHHyTJfvhKHRktHbIz1WmRsMEb1/FNDIG8fxaHoYPVAmtNynu4Tz8TWlbR6OnMtrGFIuphV8Mk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784100677; c=relaxed/simple; bh=h8Ayfh15p/outZyG3S/PIYqcrbov9ckVFA754vJaIHQ=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=kvhbkbr79pl031p1/rH+0MwhHHKzgdZdakqeiIR2Yrv1IIMnuOfuPkP4w5YVPoVbx3mT+e4t8FJnXDmVqK22JL55DiZo7c9yTkmevGyyW+08USG5Wd7XuRSds3xc7aMcZXg39uog8Twl52V55XpdsQP3SzS4XuOF0JO7Jh4DNrU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=oss.qualcomm.com; spf=pass smtp.mailfrom=oss.qualcomm.com; dkim=pass (2048-bit key) header.d=qualcomm.com header.i=@qualcomm.com header.b=flWivHx6; dkim=pass (2048-bit key) header.d=oss.qualcomm.com header.i=@oss.qualcomm.com header.b=UhpPPZG7; arc=none smtp.client-ip=205.220.180.131 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=oss.qualcomm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=oss.qualcomm.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=qualcomm.com header.i=@qualcomm.com header.b="flWivHx6"; dkim=pass (2048-bit key) header.d=oss.qualcomm.com header.i=@oss.qualcomm.com header.b="UhpPPZG7" Received: from pps.filterd (m0279872.ppops.net [127.0.0.1]) by mx0a-0031df01.pphosted.com (8.18.1.11/8.18.1.11) with ESMTP id 66F3lHLt2406154 for ; Wed, 15 Jul 2026 07:31:11 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=qualcomm.com; h= cc:content-transfer-encoding:content-type:date:from:in-reply-to :message-id:mime-version:references:subject:to; s=qcppdkim1; bh= eVZ9ZigYCDlcDM/PZqVHEcpbio13v2AmIbxFezgYnAc=; b=flWivHx6DSNcEF4l 3+WFGI5my90RIuFOWmXAH/VxAWTSY25H5DEk9L8jww59k0gz5NqgLobeUCCoRnPL hkVQWT2o39jdqbcaCjhudF01tzfSHGN+5+Fbp085SMJBeA5O9X5/il0/a6UU+JfF tFudpmaESNF+xHLhdbmvcYn7CS7pDJQJjpTGmwNQWk3N1aIbzWTvTKUYSBTPAs3q 5p462r957NYRZbi7tD/hlVGkw/zqcastK20VjPhAxYz+1eWdIBQl1FaET4C08WPo 5hVkFCG/XSgBf7Hhg8dVTiIG4IZsvjXhrSWwMu7ZFbJqrgjdtNA8gwVI40dshMNR /KwPAg== Received: from mail-qt1-f200.google.com (mail-qt1-f200.google.com [209.85.160.200]) by mx0a-0031df01.pphosted.com (PPS) with ESMTPS id 4fds9g2h1g-1 (version=TLSv1.3 cipher=TLS_AES_128_GCM_SHA256 bits=128 verify=NOT) for ; Wed, 15 Jul 2026 07:31:11 +0000 (GMT) Received: by mail-qt1-f200.google.com with SMTP id d75a77b69052e-51cab6f7517so7673951cf.0 for ; Wed, 15 Jul 2026 00:31:11 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oss.qualcomm.com; s=google; t=1784100671; x=1784705471; darn=vger.kernel.org; h=content-transfer-encoding:content-type:in-reply-to:from :content-language:references:cc:to:subject:user-agent:mime-version :date:message-id:from:to:cc:subject:date:message-id:reply-to :content-type; bh=eVZ9ZigYCDlcDM/PZqVHEcpbio13v2AmIbxFezgYnAc=; b=UhpPPZG7Z9ZraniwaIRdU9Er0GrxvJLt25PFd+pJ3yN+R37aJRjU3y9RcFI8xzkVFs zEQUrghf0TL8SszpiMu613yk8HPL0iRW14rPPokoeQfQ6yZ/BHObJbbOtvGyf5rHnGgF eVMz+9IzSZHdf/8PO8WtXNjHBfts1kW6kApZ4EefXTG6mF/FlxunIK+pJJDyuCjtmBEP rWKtgNE0n/wpAYyNdngpcbmv5b/4PV7KnqQ0lqUfL0tQuV+YinpjKbYI/xxW3XjEWEmI YUqWtBNSLl9o8Xih4p0zLtMvXM8LtBI9ySHdImIqSCbEiQwR/2rngSVnQHAcRODIJmZX XuCw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1784100671; x=1784705471; h=content-transfer-encoding:content-type:in-reply-to:from :content-language:references:cc:to:subject:user-agent:mime-version :date:message-id:x-gm-gg:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to:content-type; bh=eVZ9ZigYCDlcDM/PZqVHEcpbio13v2AmIbxFezgYnAc=; b=n7tFwGFBwDaU7d+O6DF9AY3JZ/ME4JOq+C261gUEPzlhGk+UaJ8eKRuSyDf3J2nJaT eRs5oultPoRSCFkJG7Z8YhxznyUHVFf9UQWiTrcbqOpPQDmmDpbb4FGyzSAjLxR+HiBK MfN5Td+AM+fAvUOPvK8yXVRA/to7hdATqUQMA7sNHtMqMSmVB4YdTPdPqPLpcXBTlOgY +Xy1dKipb6OO4Ml3JNI15c7IeJxIi1S0YuyEFlFD3yBSAvUw9aw/hL1PqEWVcveChuXW f3d0ZwMH87P7nmWjNtTutemoUgcT+IxcPr4xeljqRfOCwfenkial3pa2HRtYGr3schAS 0rPw== X-Forwarded-Encrypted: i=1; AHgh+RqQDFeq865JFZZu727Ok5rjeSGIweP+Z/EzOe+AERyDFRS6BXCs3hMWe01aDmkUv4IDFC1Q2O1vdGUQ78A=@vger.kernel.org X-Gm-Message-State: AOJu0YzUZWrYuriDD60t7ZEDWz+Mn2xkEUEWn6Gw2/MCF3MPbNEdphIB D/UskF9noQdY4Gxkw6BITxgC2mafS2wi+/SDAFBmw2v+kLlGnXOqHBLUmpQouZIMpA9TtMF3AbR DUegNMGeI3NyEC/Tiy+XTirCbj9vhafStofHUT3w0jriwecnAz6t1r1cSgVA77J/l86k= X-Gm-Gg: AfdE7cmH6AISPtHZS8acdykuZHRR2L+BHhV77GX2qVy3QLUjwBIOpu6TnOm2AYZqlNy c1wdSSQoHHrmLl/jBbl7iItUksnZL/BTZg8PSndyD7BcHTzHp7ow4KktihhAUd/JS2/WQU0au6S exhn/W0Z2mK/kiVHd0u9/5FdQy+yfkCAlpAQzJ7oB5YNCftUqPZThtx9NaW7V3dhUOyR5cLWoaq +bMDxgEN+RZo9xUlj+P4aHee2s/K6ISw5e8aaZcwxShfGNDxoJmq3BqPn6lWepvpnSYZYbHK8ll ukAaG24UVH0sslzGR9G9i5K7Grdkm2elmCeW/v+hIXVRkWvf4w3GbdVpsCG8m/LxNZG0BVt6gp7 xza2+KkDg4Fc/l29rjz23MtE+hE6kdJDcvxU= X-Received: by 2002:ac8:5d4e:0:b0:51c:1744:edf0 with SMTP id d75a77b69052e-51cbf289286mr135432331cf.9.1784100670973; Wed, 15 Jul 2026 00:31:10 -0700 (PDT) X-Received: by 2002:ac8:5d4e:0:b0:51c:1744:edf0 with SMTP id d75a77b69052e-51cbf289286mr135432081cf.9.1784100670440; Wed, 15 Jul 2026 00:31:10 -0700 (PDT) Received: from [192.168.120.193] ([178.235.128.140]) by smtp.gmail.com with ESMTPSA id a640c23a62f3a-c15fc29937esm790840866b.22.2026.07.15.00.31.07 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 15 Jul 2026 00:31:09 -0700 (PDT) Message-ID: Date: Wed, 15 Jul 2026 09:31:06 +0200 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH V4] i2c: qcom-geni: Add dynamic transfer timeout based on transfer length and frequency To: Mukesh Savaliya , Aniket Randive , viken.dadhaniya@oss.qualcomm.com, andi.shyti@kernel.org, sumit.semwal@linaro.org, christian.koenig@amd.com Cc: linux-i2c@vger.kernel.org, linux-arm-msm@vger.kernel.org, linux-kernel@vger.kernel.org, linux-media@vger.kernel.org, dri-devel@lists.freedesktop.org, linaro-mm-sig@lists.linaro.org, naresh.maramaina@oss.qualcomm.com References: <20260710161056.1799019-1-aniket.randive@oss.qualcomm.com> Content-Language: en-US From: Konrad Dybcio In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Proofpoint-Spam-Info: AW1haW4tMjYwNzE1MDA3MSBTYWx0ZWRfX6WuCP7apQWYz 4b2PHsmmnw/Fqf+dToXXCk6JJcGYd8NMzR5OH8VRdrryhJnW3E+g2gy5QKinuKNuUUFCYrsDlNJ IOEWZmIUcYFY7DFCpA2UbQGYIHEkvk4= X-Proofpoint-ORIG-GUID: dpB0Lu6trWWx0ap0L9fAsmO5yxzfgjEE X-Proofpoint-Spam-Details-Enc: AW1haW4tMjYwNzE1MDA3MSBTYWx0ZWRfX8JQJzTzMUxEd Uy8LqNCTJ2u+GeApiIH1SIn8yPDPfVMXp0aXqg+y7ojN27wFHmwTMIaDdvHFYn1gYpseX4voIa0 PIwllj8/NHvTAsEg1FpFz+HSm8c9YB3udTlgVSOrWdgm7m4s9dXlbdWiBxNmZ/nYFuWFzH/2/Vf NE64dQIDVeU07s24BgXtcZQPQI+rQgRi9nkm7F58z4wp84l3ip346xpPKrsua7w8KeW1FIP89wn mVMeBvAMxHvMpFsNplgYWuBhQz7ntFjkEtHjuDlQHsq3BJxWRJVYlosn3pZ6Bly8N+ZAaEzcWu5 WsRut6KyDAMcbdm/ao24arafGiHPt4zEopY1uQxHyG/sTcVTpOgYFrj5th8m4tgIVdpuFYzi22G 2gEWv1r9uZ8SdMh2BS5THsD6431FgfxpZA6EC9u/utbm/VrwULB/8ZmZyd59VRrZY5p6OWiq93+ SS/Yx4LIX9vubiEje1Q== X-Proofpoint-GUID: dpB0Lu6trWWx0ap0L9fAsmO5yxzfgjEE X-Authority-Analysis: v=2.4 cv=VoATxe2n c=1 sm=1 tr=0 ts=6a57373f cx=c_pps a=JbAStetqSzwMeJznSMzCyw==:117 a=PRfkaYvzSr8QmIIGAkY2Sg==:17 a=IkcTkHD0fZMA:10 a=RAioF0-LDSMA:10 a=s4-Qcg_JpJYA:10 a=VkNPw1HP01LnGYTKEx00:22 a=u7WPNUs3qKkmUXheDGA7:22 a=yx91gb_oNiZeI1HMLzn7:22 a=EUspDBNiAAAA:8 a=lLXzRi4vikbFFa1iuNgA:9 a=QEXdDO2ut3YA:10 a=uxP6HrT_eTzRwkO_Te1X:22 X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1143,Hydra:6.1.134,FMLib:17.12.100.49 definitions=2026-07-15_02,2026-07-14_01,2025-10-01_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 malwarescore=0 spamscore=0 bulkscore=0 clxscore=1015 lowpriorityscore=0 priorityscore=1501 impostorscore=0 suspectscore=0 adultscore=0 phishscore=0 classifier=typeunknown authscore=0 authtc= authcc= route=outbound adjust=0 reason=mlx scancount=1 engine=8.22.0-2606150000 definitions=main-2607150071 On 7/15/26 6:06 AM, Mukesh Savaliya wrote: > Hi Aniket, Thanks for addressing previous comments. > > On 7/10/2026 9:40 PM, Aniket Randive wrote: >> The driver uses a static XFER_TIMEOUT of HZ (1 second) for all transfers >> regardless of message length or bus frequency, causing unnecessary >> delays on error paths. >> >> Compute the timeout dynamically from message length and bus frequency >> with a 10x safety margin over the theoretical wire time. Add a 300ms >> floor to budget for I2C clock stretching, where a slave may hold SCL >> low indefinitely during internal processing. This detects real hangs > not only internal processing but it may go bad holding SCL low indefinitely. >> 3x faster than the old 1s static timeout. > Meaning, in such case/scenario, don't need to wait till fixes timeout. > I guess, 3x faster is relative to the 1 sec, but for larger data and slower frequency it may not be 3x. Hence, correct it accordingly. >> >> For GPI multi-descriptor transfers, use the maximum message length across >> all queued messages as the per-completion timeout. >> >> Signed-off-by: Aniket Randive >> --- [...] >> +/* 300ms floor: budget for clock stretching; slave may hold SCL low indefinitely */ > Already explained in commit log, can remove second part. This is very much non-obvious, please keep it Konrad