From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 3885637F01A; Fri, 14 Aug 2026 21:19:55 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786742396; cv=none; b=NwZBpMJKkaBVlqk3JJe+S+GDcBkd1kAMu/r2oJN1Ty1hSOCtxGWZifBpTrx7SiYOeiMCU/9jZP1Mq7fH9GHgJwP47W+JIPIzouYnDmdQ6ah1u+a0hq6q/MnaL0rF80vZ+W+edKJvVlODlOrxD11onU4YvhA67q3GmIeWHh0s2Wk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786742396; c=relaxed/simple; bh=iRAWwpqyHCsCEBig8Ggg6vWc3y0LM0HV+hjBv8vbQ6c=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=WEjt6LjebMWE9hSxYyBw4NiWZx+Ls0/uTgrqt/wMWqMd6D+kyu1RPjIyv/lXYjjdhkrTcJOyy9avt9TMva3otd2bg0x6dfGS9NM/pUVlpi8ZWqlsMWOYXZqeYMBYbUQ1P/uO/hh6dAQ+CXbPZxYpN8PZXu41SU7QbJR+lTWf8HA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=kW4i02dh; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="kW4i02dh" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E01611F000E9; Fri, 14 Aug 2026 21:19:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1786742394; bh=8xyewwSgf7Y2TJ9EZNTnjEdF4u56f4myYdpmZfysO44=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=kW4i02dhygVEUm0S604lBmWnhC78bEyEKtqnBskM2MZivHq955nsK8V0A/DHWyrS1 QxvDvQ9M6IPJb6JUx8ZtivmL3sfoBa1lsvGRphsHup3/7Wzi1nLpLGmrpv6olBXtnF xQDjFfHgjDfyWy66vQfDxLKPnF4a9PATxaMMNZ4jQBP4lJZSiMYWWDHyXkip9hpCV5 W9pstcBcB0DUHyPc7q6rmoxkQnT5daaUG++eItaw83mnZFYc0gWukzx+oJGQB8QPZm +LHpAmCYCcjIHX5DVBH1DoKBSwdil2j1sFG25fgfkB0vP5Qv5phV1Jn3d6RzCqmTrh flW9RzjEUAmvQ== Date: Fri, 14 Aug 2026 23:19:51 +0200 From: Andi Shyti To: Hardik Prakash Cc: linux-i2c@vger.kernel.org, linux-gpio@vger.kernel.org, wsa@kernel.org, andriy.shevchenko@intel.com, mario.limonciello@amd.com, brgl@bgdev.pl, basavaraj.natikar@amd.com, linusw@kernel.org, nathan@kernel.org, chaitanya.kumar.borah@intel.com, linux@leemhuis.info, regressions@leemhuis.info, linux-kernel@vger.kernel.org Subject: Re: [PATCH] Revert "i2c: designware: defer probe if child GpioInt controllers are not bound" Message-ID: References: <20260814100719.9548-1-hardikprakash.official@gmail.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260814100719.9548-1-hardikprakash.official@gmail.com> Hi Hardik, On Fri, Aug 14, 2026 at 03:37:19PM +0530, Hardik Prakash wrote: > This reverts commit 0a4bb2abc3e56d7be6e69b050c88ba52c87e22bf. > > The reverted commit causes a regression on ThinkPad T14s Gen 4 (AMD): > the touchpad's I2C controller fails with lost arbitration errors, > because it delays i2c-designware's probe by roughly 500ms, which > shifts the touchpad's first HID descriptor fetch into a window where > the platform's embedded controller is still acting as a secondary I2C > bus master. Debug tracing confirms the GpioInt dependency check itself > behaves correctly (it defers appropriately and confirms the GPIO > controller is bound); the arbitration failure happens roughly a > second after the check passes, when i2c_hid_acpi's own probe attempts > its first transaction. > > The original fix is still needed for the Lenovo Yoga 7 14AGP11 > touchscreen race the commit addressed, but a corrected version will > be resubmitted once the EC bus-mastering interaction is understood > and handled properly, rather than reintroducing a different > regression on more widely-used ThinkPad hardware in the meantime. > > Reported-by: Thorsten Leemhuis > Closes: https://lore.kernel.org/all/b4a4eadb-282f-464c-843a-19d415a34d0c@leemhuis.info/ > Signed-off-by: Hardik Prakash merged to i2c/i2c-2. Thanks, Andi