From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out-178.mta1.migadu.com (out-178.mta1.migadu.com [95.215.58.178]) (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 A641534BA56 for ; Fri, 6 Feb 2026 10:12:13 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=95.215.58.178 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770372734; cv=none; b=pHnXuPa+fH5VxZrkKjULTq3bRZRdkmiwhL4iYWX/TJ/f9LBZZjpqMr6ZAn1AOOKSosxhWakDmLaLX0iYOnzyC/MQpd5YH7TetpxCWolU0447t9eMydDIa0aejvztHsunDXh4+Ktsa4+xqxdsjp7s/LRUIsMFczh4nTRUcO2LZgs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770372734; c=relaxed/simple; bh=HvdRmzw1qTvrLbyWBS3sDsuy7TpzPvVFaI83A0h49+Y=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=CFCIQ9y++Kgr3jV8u5Is4OqCgOMtOqRcs0SMXrLjCJ6StulIIsYRMYd8Sl/BoQFsaHpZpw9YIQ0iBYpYYWyFI35ZjiOxwK4v9fA/MsqMXU6t+jdaLmy7cm27Wz3QqbMP2j+r4h1HUZvtQMkyaskfDSPquXjcUl8VGNQfqA1Ovao= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=s1hZQdPC; arc=none smtp.client-ip=95.215.58.178 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="s1hZQdPC" Message-ID: <601f0c4b-52d8-4b60-96bf-f2d65f8073d8@linux.dev> DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1770372731; 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=DhaAgJyKGpAxu69onmTYpr1zMQl+4LY07Xc1GM3wQlQ=; b=s1hZQdPCFE8qhcU9pfJ34OOPrLOGMEaldYRioPOYeFAwkarsS9aJKjFZe1mnuBWM0/mgEF XMpM54KSCIaU4FlVnTqz3BzQBbPXVzzhVsYng3GqfFD+5XsqR/WpfOLetaMX15ajsu6wT+ P0mlT45JQxV26mer0sXRaGq9c0djpU0= Date: Fri, 6 Feb 2026 10:12:04 +0000 Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Subject: Re: [Intel-wired-lan] [PATCH iwl-next v3] igb: Retrieve Tx timestamp directly from interrupt for i210 To: Willem de Bruijn , Sebastian Andrzej Siewior , Willem de Bruijn , Jakub Kicinski , Paolo Abeni , Eric Dumazet , "David S. Miller" Cc: "Loktionov, Aleksandr" , Kurt Kanzenbach , "Nguyen, Anthony L" , "Kitszel, Przemyslaw" , Paul Menzel , "Gomes, Vinicius" , "netdev@vger.kernel.org" , Richard Cochran , "linux-kernel@vger.kernel.org" , Andrew Lunn , "intel-wired-lan@lists.osuosl.org" , "Keller, Jacob E" References: <20260205-igb_irq_ts-v3-1-2efc7bc4b885@linutronix.de> <20260205100347.ssTBDAI_@linutronix.de> <6a0f4cbb-e8b3-4f0e-b7f1-7f9ca5cba97d@linux.dev> <20260205145104.iWinkXHv@linutronix.de> <66925f09-ef9f-4401-baec-7d4c82a68ce3@linux.dev> <20260205164341.pJvni8kA@linutronix.de> <76acd5cc-eb6f-4c56-a5e6-f6413736afbb@linux.dev> Content-Language: en-US X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Vadim Fedorenko In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-Migadu-Flow: FLOW_OUT On 05.02.2026 21:41, Willem de Bruijn wrote: > Vadim Fedorenko wrote: >> On 05/02/2026 16:43, Sebastian Andrzej Siewior wrote: >>> On 2026-02-05 16:27:03 [+0000], Vadim Fedorenko wrote: >>>>> So the only thing that bothers me is the read_lock_bh() in >>>>> skb_may_tx_timestamp() which deadlocks if the socket is write-locked on >>>>> the same CPU. >>>> >>>> Alright. Now you make me think whether we should enforce OPT_TSONLY >>>> option on socket which doesn't have CAP_NET_RAW? Then we can get rid of this >>>> check, and in case sysctl was flipped off - drop TX timestamps as >>>> it's done now? >>> >>> This would "fix" this problem for all users which do deliver the >>> timestamp from their IRQ handler instead of napi. There are a few of >>> those… >>> This would be considered stable material, right? (despite the fact that >>> we have it for quite some time and nobody complained so far). >> >> cc: Willem as he is the author of the check introduced back in 2015. >> >> But it's more like a question to maintainers whether it is acceptable >> way of "fixing" drivers or it's no-go solution > > Requiring OPT_TSONLY unless CAP_NET_RAW would break legacy users. Well, they are kinda broken already. Without OPT_TSONLY and CAP_NET_RAW all TX timestamps are silently dropped. To receive these timestamps users have to get CAP_NET_RAW permission, and it will work with the updated logic as well...