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 713E937B011 for ; Tue, 9 Jun 2026 15:09:22 +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=1781017763; cv=none; b=eEAmiS2Um9XaIdv2sxORilzxTyrcW58w6DtMfqT+naa5vln98AeKWmuY9TPfSKMRMQDzFBrVlGGlwDYdtzP8yx3UNRyz+XlYN6ddQDzvqLa3me8iSydEgYEC+Wjf19kl1yTIPDB2W5LlHa9kFFlAtiN0RRcgfq2mqDPTELDLPp8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781017763; c=relaxed/simple; bh=IMVCwKUih2Uqw58wkHLuxSJ2gYUl2swmL+hraZIoj6k=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=t4IoNh6UVwPEjYsU8a14IJgtDMI3h0NaE1nb01DE/GJMxPvhzGGhuXHJJ0OfE869nbjO+rGVlaAu216DM3m0nZNtMv0DE75x3aJLAbVV/7lhPrT9b/nUmgaV41w4eyIRV+eYnF80MZR63lmIE0D1bPT1kPjZpeXFGTlO76OcpDs= 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=JxLBbwhH; 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="JxLBbwhH" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1781017761; 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=C7fPu4IonwtQPpiECu+HiO3W2XcnZJwWMr5HGoOfkZs=; b=JxLBbwhHKT/y2bphIdpuJIIW2GRxoNIlGGq70Eh+VEtzZRWDLSafeRpD5pwX3fedNQhwXH PkR0jeJ0GrVdzqZMxHhpcuPwyZN+n2QqhUQWfdRKFEFQsa/4twbp8+PV6w5a99fXD+VYFO QN4DHVjVaTVcfVdkG9YIeZu3vmyCBoU= Received: from mx-prod-mc-08.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-609-q3YY3ZGyNOOBIH5Ue4XL-Q-1; Tue, 09 Jun 2026 11:09:18 -0400 X-MC-Unique: q3YY3ZGyNOOBIH5Ue4XL-Q-1 X-Mimecast-MFC-AGG-ID: q3YY3ZGyNOOBIH5Ue4XL-Q_1781017756 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-08.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 90BAB184EB4C; Tue, 9 Jun 2026 15:09:15 +0000 (UTC) Received: from [10.44.34.233] (unknown [10.44.34.233]) by mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id 5E3151954B00; Tue, 9 Jun 2026 15:09:11 +0000 (UTC) Message-ID: <0011d6be-2ffb-4584-9ad7-86b3da447412@redhat.com> Date: Tue, 9 Jun 2026 17:09:10 +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 net-next v5 1/4] dpll: add DPLL_PIN_TYPE_INT_NCO pin type To: Vadim Fedorenko , Jakub Kicinski Cc: Arkadiusz Kubalewski , netdev@vger.kernel.org, Jiri Pirko , "David S. Miller" , Donald Hunter , Eric Dumazet , Jiri Pirko , Michal Schmidt , Paolo Abeni , Pasi Vaananen , Petr Oros , Prathosh Satish , Simon Horman , linux-kernel@vger.kernel.org, Grzegorz Nitka References: <20260531194423.383366-1-ivecera@redhat.com> <20260531194423.383366-2-ivecera@redhat.com> <20260603185037.05f8c6a0@kernel.org> <20260604081649.1ae5302d@kernel.org> <3c5e01f5-8563-41a3-964f-13fcb80383b7@redhat.com> <9b493ce2-6213-4a29-aeee-b473b6b16fa1@redhat.com> Content-Language: en-US From: Ivan Vecera In-Reply-To: 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 6/9/26 12:24 PM, Vadim Fedorenko wrote: > On 08/06/2026 16:30, Ivan Vecera wrote: >> On 6/8/26 1:33 PM, Vadim Fedorenko wrote: >>> On 04/06/2026 17:42, Ivan Vecera wrote: >>>> On 6/4/26 5:16 PM, Jakub Kicinski wrote: >>>>> On Thu, 4 Jun 2026 17:01:36 +0200 Ivan Vecera wrote: >>>>>>> Purely going on intuition here but feels like NCO should be a mode >>>>>>> (enum dpll_mode) rather than one of the input pins? >>>>>>> >>>>>>> More acks here would be great, Vadim, Arkadiusz, Grzegorz... ? >>>>>> >>>>>> I had a long discussion with Jiri about this and we agreed finally >>>>>> that dpll_mode represents a reference (input pin) selection strategy >>>>>> mode and not a DPLL device running mode. >>>>> >>>>> Long discussion? I see 2 emails ;) Let's hear from others. >>>>> (thanks for the link BTW, _if_ there's a v6 please put it in the cover >>>>> letter) >>>> >>>> I called him... he explained me 'why?' in detail. >>>> I also appreciate others' opinion. >>> >>> Well, NCO mode means manual operation of frequency tuning. Does it mean >>> that different tunings may be applied to different out pins of DPLL >>> device? My assumption that it's not possible, and in this case NCO is >>> property/mode of DPLL device rather than single pin. >> >> The NCO pin is only one per device... When it is connected, then the >> device the pin is connected to is switched to NCO mode. In this mode >> the device is not locked to any input reference and the driver allows >> tuning of the DPLL frequency manually via PTP interface. >> >> Such tuning is applied only to output pins associated with this device >> but not on others. >> >> Examples: >> DPLL0 is driving output 0-3 and DPLL1 is driving output 4-7. >> Then if you switch the DPLL0 to NCO mode (makes NCO pin connected to it) >> then frequency tuning (via PTP) has only influence on output 0-3 (the >> same tuning is applied). Outputs 4-7 are not touched as they are driven >> by DPLL1 (that can be locked to some input reference). >> >> If you switch both DPLLs to NCO, then frequency tuning for DPLL0 affects >> output 0-3 and tuning for DPLL1 output 4-7. > > Technically speaking you have described per-device behavior. And NCO pin > can technically be virtual, just a configuration option via normal > device communication channel. Doesn't feel like pin's attribute. Back in > a days of DPLL RFC patches we have discussed the option with Arkadiusz, > AFAIR we were leaning towards per-DPLL state for this case. Frequency fine tuning is not the subject of this patchset. It is currently part of the PTP API via the .adjfine() callback. I have not added this feature yet, because it would be a duplication of part of the PTP API, but if there is a consensus, we can add it as a per-device attribute. Something like dpll device attributes: * fractional-frequency-adjust - corresponds to .adjfine() - tunes dpll device frequency (usable mostly in NCO mode because when the device is locked to physical reference then its frequency is driven by this ref) * phase-adjust - corresponds to .adjphase() - adjusts phase of all outputs driven by this dpll device performed at once Thanks, Ivan