From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) (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 9302833509B for ; Tue, 13 Oct 2026 10:10:38 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.129.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791886241; cv=none; b=ogleh8b/gEx1xxYdhwZwvxdfX/7ESj19fxpBFWuV3amZR6kpKP2vc82GLNrHX2pXKcMpcGBDcI1pgX1HA3E6SwyEnXfNoUEnBEevLZogi7HYJDKDRTDlGti6aGj8JfqXl4d1fq8D/ec33GKTYajeSy36IK7jF5bmcqmwr7eEpj8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791886241; c=relaxed/simple; bh=rPU66RTkPOm1XDuhtTsXUMgzuLrL8zDkGyJKBwoH8qE=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=F5TikU3ggClbKGwyHWwT7gr9sPFXsl99X772GPKkFDdUnGZVFQvxf5dm1oGZryx30LXTLvSbmgM6Tcle64CxmScBC+hopupTOEyaVPe4zMmrSAlFUQsmZMpBcqs4Ae2STQsVxN3kcCr4GUYaqaSTG86qAtN3dbcAuzSdMfCsij8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=T4mTkuxs; arc=none smtp.client-ip=170.10.129.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="T4mTkuxs" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1791886237; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=h1p+nu/hoPn9auVbQdjmwrR26tibasmC89HS5LmsL5A=; b=T4mTkuxsyzsFfMGgkExIZ09ZaD71AS/5z8meiBfiwXFkJ7lUCOTKIR4No/F56xkCqbUjf9 uty6UzzoiCgSmI9lNXXunWs5/2Qdh7pFHnFZRx/PXMTPROGxl2ipxmYn7fT18PM6DOnEm2 rjvlJpYEC4StYGRmNjd1bdJDhVy+LDY= Received: from mx-prod-mc-06.mail-002.prod.us-west-2.aws.redhat.com (ec2-35-165-154-97.us-west-2.compute.amazonaws.com [35.165.154.97]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-207-ZF0yr0d4MZuGG3faoNCPiA-1; Tue, 13 Oct 2026 10:10:34 +0000 X-MC-Unique: ZF0yr0d4MZuGG3faoNCPiA-1 X-Mimecast-MFC-AGG-ID: ZF0yr0d4MZuGG3faoNCPiA_1791886232 Received: from mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.12]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-06.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 84FA1180B5DA; Tue, 13 Oct 2026 10:10:31 +0000 (UTC) Received: from [10.43.2.199] (unknown [10.43.2.199]) by mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id 637BA1956086; Tue, 13 Oct 2026 10:10:28 +0000 (UTC) Message-ID: <1772855d-e738-495e-abb0-7f064a3e3700@redhat.com> Date: Tue, 13 Oct 2026 12:10:27 +0200 Precedence: bulk X-Mailing-List: devicetree@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH net-next v12 11/12] dpll: sit9531x: add support to get phase offset on the connected input pin To: Ali Rouhi , Jiri Pirko Cc: Vadim Fedorenko , Arkadiusz Kubalewski , Jakub Kicinski , Paolo Abeni , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Carolina Jubran , Oleg Zadorozhnyi , "devicetree@vger.kernel.org" , "netdev@vger.kernel.org" , "linux-kernel@vger.kernel.org" References: <20261009183151.78497-1-arouhi@sitime.com> <20261009183151.78497-12-arouhi@sitime.com> Content-Language: en-US From: Ivan Vecera In-Reply-To: <20261009183151.78497-12-arouhi@sitime.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 3.0 on 10.30.177.12 On 10/9/26 20:31, Ali Rouhi wrote: > From: Oleg Zadorozhnyi > > Report the phase difference between a PLL's reference and the PLL itself, > which is the loop's own residual error and therefore trends small on a > locked device -- that is the measurement, not an artefact of it. > > The value comes from the on-chip time-to-digital converter, read through > the debug window: unlock the window, point it at the converter, then read > the trigger register, which latches a fresh sample and returns the > previous one. It is read three times per sample for that reason; a single > read hands back the sample from the last call, so a repeated measurement > would look perfectly steady while saying nothing. The offset keeps the > fraction of a picosecond the converter resolves. > > Only the input the device feeds a PLL has a phase offset against it. > For any other pin there is nothing to measure and zero is reported, > because the core abandons an entire pin dump on an error from any one pin. > That pin reads zero too when no sample was taken: the PLL is not > tracking, drives no un-muted output, has no usable VCO rate, or the > device moved it off the pin, or the lane lost its signal, between the > check and the sample. > > Signed-off-by: Oleg Zadorozhnyi > Assisted-by: LLM > Signed-off-by: Ali Rouhi > --- Reviewed-by: Ivan Vecera