From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mx0a-0031df01.pphosted.com (mx0a-0031df01.pphosted.com [205.220.168.131]) (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 1DEA9392C21 for ; Wed, 15 Jul 2026 04:06:40 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=205.220.168.131 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784088402; cv=none; b=AaIkKp8hRn7DV3Inbmjh/ZUM6yRR3pSwoe0kk9ut5qJycAuQT6zbWvWyi08Hxka035Y41goANb/uC6H1vpQelTzPwkaoz7FqV4sR4FUNjDeHAqftQik3LmBt40EPALvarTnA1FbTWRyuud2Dv8P3/WtbklPzPx/YCnTsSalU+7M= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784088402; c=relaxed/simple; bh=0EFshVqSrc8f7OStgTf8hZCJkjVP5CzhGdQcqZKvRV4=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=qLs/FbeK9DmE7H/A0ZU82VUnmE22osuj0is9i6YMrb6TR+x90tsk2+eHIRQXkPbuDGawu4qi+ebhxjrwFIGokQgmMaaWaIo6s4VlQZ68ecAG7GV+GmG5/Pzmp3ttkhYZNSt1kYVnfl/7G2YfFge3ECA32/XW5luVXwJgomtgRp4= 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=MBX2aI/E; dkim=pass (2048-bit key) header.d=oss.qualcomm.com header.i=@oss.qualcomm.com header.b=UjROiSJA; arc=none smtp.client-ip=205.220.168.131 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="MBX2aI/E"; dkim=pass (2048-bit key) header.d=oss.qualcomm.com header.i=@oss.qualcomm.com header.b="UjROiSJA" Received: from pps.filterd (m0279863.ppops.net [127.0.0.1]) by mx0a-0031df01.pphosted.com (8.18.1.11/8.18.1.11) with ESMTP id 66F3l6A72596256 for ; Wed, 15 Jul 2026 04:06:40 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= aq8pKEu+zdq3GBZfc94BkwVIZ1D/MyJMoeF2wETynLU=; b=MBX2aI/E267mc+Ri Ae2koslafqgvNgkufljnooxJZ/mYOzcNmTBJ1O/GCjLaXODOL5WMxsAmoeNgAgIE T7+FdX/FegTXjic/uied/NqaF7LWQDNJfU6Z6YMNMCltGUy1bNIjc9L6kPkMFrFZ 0PTkWf1iKlUWhR/crNap7gH52HnFbIWZGWp+fcWYv42fyODmgAh32aswrBpNIXkz K2UbaBp2xUTQxdDOqPMJCL225uzX9oFNVb+WcMj/cf21/x0P58UnoF+IjHZrgMk/ iF3LCwyM27PRzeKEwuDkKgt46NW5UhMR4Thwe607JpSy0awSC/QxOrSjpiQOmvsp AcvVnw== Received: from mail-pg1-f197.google.com (mail-pg1-f197.google.com [209.85.215.197]) by mx0a-0031df01.pphosted.com (PPS) with ESMTPS id 4fdmjq35v9-1 (version=TLSv1.3 cipher=TLS_AES_128_GCM_SHA256 bits=128 verify=NOT) for ; Wed, 15 Jul 2026 04:06:40 +0000 (GMT) Received: by mail-pg1-f197.google.com with SMTP id 41be03b00d2f7-c88aab7c1fcso11974529a12.3 for ; Tue, 14 Jul 2026 21:06:40 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oss.qualcomm.com; s=google; t=1784088399; x=1784693199; 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=aq8pKEu+zdq3GBZfc94BkwVIZ1D/MyJMoeF2wETynLU=; b=UjROiSJAdTRU1jHdyKEKlBHAUM/aRPkVkhsT6lIrHFtYObK0ujpxOyzGsYm+t6Lqy0 qcMOL5yGUaMfPfVMA4VZlJ8zXJHDGT6/9NaN7V0R0hk/+HYj97UtGwARK6mBywpgsJHQ CL8/vKcHD+vP7lOFJDGGXtrTeCk4t4l+K63v61PPDWIFFXflQqbkQe32BSvsIsmgLQpg 7Oi8oPQpADPtV4fUDOTqa2mCtUBp5L4fAzcGIWzpgvqslljtqqis4cNtQkvT6i+2TNUH 0kpJwavRD+h+jn7643po7F4z9y8AJLOu+Q78sVUcXOMBsdLq1sihuMKHdMCTEhy8N6B5 AFGw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1784088399; x=1784693199; 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=aq8pKEu+zdq3GBZfc94BkwVIZ1D/MyJMoeF2wETynLU=; b=kEdWgt9s3lMQiy+ABO8nR7UdONJ+S3Go4kDvze3U+gMhd2y9uUPEpgRzvUSkB8yt3G oNqJQRFiYzGdW5iVRyK4pSr8ioY4jk+MZ/vjyjl+mlqWY8ubv/IWwAzU7cPasdIlRGWh 1f3ImiwwGk9Pa8Jobh+mDXahdl9A6QI9ZAuFnvLuqo8jQXDaAi4j92h9xKKrS2V+ah8S M+RiJp3RmlTbbCcVq/w7BhrUT+6NSkb39LiFvyfBvfXVE6uAhtpBpQwDWePJAG4f6tml iPYgGlduP/mJt/Ch0VNSztCapeDN1z+1MZG1kxnB8+qt4v6BqZtAWBCzr18ihNOMXFZS tsxw== X-Forwarded-Encrypted: i=1; AHgh+RrJ+Td8ek1ksCD3UYEWF/CC2QoIoVo+GiU0ilQ2cisTHY48syMf3ghHxM6YZMbQVtQGlN4ingapabUA1iI=@vger.kernel.org X-Gm-Message-State: AOJu0YwZsKvOfUlVU4KQNsC9xzcV4das8poQtQYrhO54toiCwiIt3A0O R11TxxkW0DwWMa7RiEShZOTfHUWa+R0/+xdJJ0Owcx5nL2klZjBtj7XuKReWwWP3pMYLGJ5UYJx 0byty2Ia3CGIJsKwnZ4zxqbdlCFTHuYDkoP8zgIcGEFDdB7YMr45cHbHs6d8Hd2qiTG8= X-Gm-Gg: AfdE7cnllgeDuUedKy1l+AUhmsV7OCM0tZ7tSmbVst5OXBKLswQjAdNDN4GZaXwP+bA 1/wMrMOZzsb23IOTDL18DUmjrctQWxlYkbcluhvVaxDQZHgtPuZn9MzGtf3hG3UrBoi78Z/l7Kh f2PNkQoULfjmhTx5ThiKQeTSBJ0C+jrZriqZTgi1dTJVzDtnhbwKQxO+h9LfnaXrQ4uaEriU7Yv /LQm3otLArDPSU06nnZpUtZHC4bvkeQjsVJqbYxZK6mh20xYd4UAbenfk5mDBIrj5p84VSQuled elu3ofKltuuBY6NX3PZbqdpOuaQacsapdsWgS0fUyHWgb069l/bTBy3OEP/Mp7A3ahSIgCMeQkG Okk3vFWtZ/cEdedUPoAZxVanxJRtoUY55FgwpKxQfL/UGZw== X-Received: by 2002:a05:6a21:8cc9:b0:3c0:9c18:d5a6 with SMTP id adf61e73a8af0-3c35729077fmr6943834637.67.1784088399581; Tue, 14 Jul 2026 21:06:39 -0700 (PDT) X-Received: by 2002:a05:6a21:8cc9:b0:3c0:9c18:d5a6 with SMTP id adf61e73a8af0-3c35729077fmr6943801637.67.1784088399121; Tue, 14 Jul 2026 21:06:39 -0700 (PDT) Received: from [10.217.219.142] ([202.46.22.19]) by smtp.gmail.com with ESMTPSA id a92af1059eb24-13b9a67c217sm27006165c88.8.2026.07.14.21.06.35 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 14 Jul 2026 21:06:38 -0700 (PDT) Message-ID: Date: Wed, 15 Jul 2026 09:36:33 +0530 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: 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: Mukesh Savaliya In-Reply-To: <20260710161056.1799019-1-aniket.randive@oss.qualcomm.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Authority-Analysis: v=2.4 cv=LqmiDHdc c=1 sm=1 tr=0 ts=6a570750 cx=c_pps a=rz3CxIlbcmazkYymdCej/Q==:117 a=fChuTYTh2wq5r3m49p7fHw==:17 a=IkcTkHD0fZMA:10 a=RAioF0-LDSMA:10 a=s4-Qcg_JpJYA:10 a=VkNPw1HP01LnGYTKEx00:22 a=u7WPNUs3qKkmUXheDGA7:22 a=yOCtJkima9RkubShWh1s:22 a=EUspDBNiAAAA:8 a=ENRykshp9vPgoFS4LJQA:9 a=QEXdDO2ut3YA:10 a=bFCP_H2QrGi7Okbo017w:22 X-Proofpoint-GUID: QtZMSUPo3ciYPUQTq6KCrA7JoD2xC9mA X-Proofpoint-Spam-Details-Enc: AW1haW4tMjYwNzE1MDAzNCBTYWx0ZWRfX+9vykl6aRWbk Qmxwo27kgOVt7m9ax0NmeQMb1Lsa1p5MU7gL4elEZziTslfW1bCWRg0d+/9s0gSIS0f0RXgTKva 5SsdMw+X5a2qHF5lk9fPyG5QavGmEkrSGkgsyYskgaqSBGTKY6Kv182drX4IsMg7FGY0TdC3Oy+ RBjSwPw7UH+TjK115ugczHc7b634tC7swA0yHDjv3jU+o0nZlN0YUo7/hNAJmNqqXbRANLjpAD5 gFONtLWGh3tgpHv8LI7VpYhOWtF96hwlPj4JPx8RQowZicUinHlWhndoymIWOt93UsUjsdIJPNp 5eWxti3BLMm0bXHgMHD471QdcaNX1o8wDwPVWmLngSqEW/ySz2jJRUt9ICGuyR0YTHg/8Z0lrea 1NMWiDW8kEssT+1rz2WSdr29zafAVjlkcJTosM1nVvjRNgkCDm3AiXs/umVpKfKBCm7qeAAQE3J ss+5FDoBP087H1eumYg== X-Proofpoint-Spam-Info: AW1haW4tMjYwNzE1MDAzNCBTYWx0ZWRfX9SQHzlVF7xqF eF/LTrwjNHa+KUqPHS9fuxIzhxl4IQw/6b/5z71bauvXaaGhmoITTJer+2+uu0Q6L8eyK2HdvV0 FqQGi6eVAJedxiGLbQRr5hoE8uggn5c= X-Proofpoint-ORIG-GUID: QtZMSUPo3ciYPUQTq6KCrA7JoD2xC9mA 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 suspectscore=0 priorityscore=1501 phishscore=0 lowpriorityscore=0 spamscore=0 bulkscore=0 clxscore=1015 adultscore=0 impostorscore=0 malwarescore=0 classifier=typeunknown authscore=0 authtc= authcc= route=outbound adjust=0 reason=mlx scancount=1 engine=8.22.0-2606150000 definitions=main-2607150034 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 > --- > > Changes in v4: > - As per konrad suggestion used mult_frac() for bit_usec to avoid intermediate Do not keep space before starting, directly start with "- As per....." > overflow on 32-bit targets. > - Updated the commit message and added a driver comment explaining the > rationale for the 0.3-second minimum timeout floor value. > > drivers/i2c/busses/i2c-qcom-geni.c | 46 +++++++++++++++++++++++------- > 1 file changed, 36 insertions(+), 10 deletions(-) > > diff --git a/drivers/i2c/busses/i2c-qcom-geni.c b/drivers/i2c/busses/i2c-qcom-geni.c > index 96dbf04138be..c5c3adc8ec77 100644 > --- a/drivers/i2c/busses/i2c-qcom-geni.c > +++ b/drivers/i2c/busses/i2c-qcom-geni.c > @@ -74,9 +74,13 @@ enum geni_i2c_err_code { > #define PACKING_BYTES_PW 4 > > #define ABORT_TIMEOUT HZ > -#define XFER_TIMEOUT HZ > #define RST_TIMEOUT HZ > > +/* 9 bits per byte (8 data + 1 ACK), 10x safety margin */ > +#define I2C_TIMEOUT_SAFETY_COEFFICIENT 10 Add a line space to make it look clean > +/* 300ms floor: budget for clock stretching; slave may hold SCL low indefinitely */ Already explained in commit log, can remove second part. > +#define I2C_TIMEOUT_MIN_USEC 300000 > + [...]