From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp-out3.simply.com (smtp-out3.simply.com [94.231.106.210]) (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 BD8542E229F; Wed, 28 Jan 2026 08:35:07 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=94.231.106.210 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769589310; cv=none; b=J5GdZ9hSdsoyWICfCsTB2opqg6mEIr/syF3+JTwi8AqwOFA6nj4oDapJp7xPuVZXwkhMCVu/JZLczab3ArRzqT7N7PyilK5tFyOtjfFCFLhc9dGrGUOWts/rlbAYYeMD0ukSvNALPntVweMjgL6suUr0HHQNEA7JysGNakpyfM8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769589310; c=relaxed/simple; bh=u7n4BK5mb9uf7qoFzv+BHOmfoPb4EHRhhut00h7FOSg=; h=Message-ID:Date:MIME-Version:Subject:References:From:To:Cc: In-Reply-To:Content-Type; b=feL1JEKkEe3czaEyUGa+YHCdr11RDWPaZ3AfXp7lj3F3EikBsCvOwXAkmVpzibf5LyFkfDDLeQgEjK8bJhm43UtBq29M+hY3vTEyE5K8lmmQ2RgADK9t4K/p3pCOe3h1Vogo0pBsslOF6f799S3fMVJvX4PBgcycH9zdPQijc7k= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gaisler.com; spf=pass smtp.mailfrom=gaisler.com; dkim=fail (0-bit key) header.d=gaisler.com header.i=@gaisler.com header.b=S4dWOUJW reason="key not found in DNS"; arc=none smtp.client-ip=94.231.106.210 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gaisler.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gaisler.com Authentication-Results: smtp.subspace.kernel.org; dkim=fail reason="key not found in DNS" (0-bit key) header.d=gaisler.com header.i=@gaisler.com header.b="S4dWOUJW" Received: from localhost (localhost [127.0.0.1]) by smtp.simply.com (Simply.com) with ESMTP id 4f1FvY5HMYz1DHbd; Wed, 28 Jan 2026 09:35:05 +0100 (CET) Received: from [192.168.0.5] (h-98-128-223-123.NA.cust.bahnhof.se [98.128.223.123]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (Client did not present a certificate) by smtp.simply.com (Simply.com) with ESMTPSA id 4f1FvY1CB3z1DDXS; Wed, 28 Jan 2026 09:35:05 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gaisler.com; s=simplycom2; t=1769589305; bh=t4Gj4mMZQzBSEUkRqGV7U26TwgSW1EG6pmEqN7Gvj90=; h=Date:Subject:References:From:To:Cc:In-Reply-To; b=S4dWOUJW+HnjYLW2x2BxP387LEloRsHuJCfVlFsjpj/zAnQJKqx34m1/TImoQZCIv h6F1PnzJ+eulgJTLc062VEB8NtKQqzfu4J4Fuyd8gGtbt99xZGx2oUlZ82Lbat+ZXl 38jTT7fBz+oYDBT5y+t1AYeNzaVekT4laFZjxSo6MejSOPchAqOIUCUgagMyLM8WKE b8h1xq9g8cu/uWMReBq2w5XEVTsrv4T5Jd+GVxWiPO3oask8umDVLMnzNuWLmd6MWv iu9abioC8O9pJVHHBeA18jFELspm9VjAZpWWHxz1Pys4ATDPi2mXCseKKWFKSfzyai /asFx7Ov+vBHQ== Message-ID: Date: Wed, 28 Jan 2026 09:35:04 +0100 Precedence: bulk X-Mailing-List: linux-can@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v3 10/15] can: grcan: Add saving and restoring of CAN FD baud-rate registers References: <20260122121038.7910-1-arun.muthusamy@gaisler.com> <20260122121038.7910-11-arun.muthusamy@gaisler.com> <20260123-original-manipulative-bulldog-07cf38-mkl@pengutronix.de> Content-Language: en-US From: Arun Muthusamy To: Marc Kleine-Budde Cc: robh@kernel.org, krzk+dt@kernel.org, conor+dt@kernel.org, mailhol@kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-can@vger.kernel.org, Daniel Hellstrom In-Reply-To: <20260123-original-manipulative-bulldog-07cf38-mkl@pengutronix.de> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit On 1/23/26 15:00, Marc Kleine-Budde wrote: > On 22.01.2026 13:10:33, Arun Muthusamy wrote: >> From: Daniel Hellstrom >> >> While reset the GRCAN baud-rates are preserved, since GRCANFD has the >> baud-rate in different registers we need to add saving of those >> registers too. >> >> Signed-off-by: Daniel Hellstrom >> Signed-off-by: Arun Muthusamy >> --- >> drivers/net/can/grcan.c | 12 ++++++++++++ >> 1 file changed, 12 insertions(+) >> >> diff --git a/drivers/net/can/grcan.c b/drivers/net/can/grcan.c >> index a2a5a5c868ff..0ee6e9bfbe7f 100644 >> --- a/drivers/net/can/grcan.c >> +++ b/drivers/net/can/grcan.c >> @@ -517,15 +517,27 @@ static void grcan_reset(struct net_device *dev) >> struct grcan_priv *priv = netdev_priv(dev); >> struct grcan_registers __iomem *regs = priv->regs; >> u32 config = grcan_read_reg(®s->conf); >> + u32 nbtr, fdbtr; >> + >> + if (priv->hwcap->fd) { >> + nbtr = grcan_read_reg(®s->nbtr); > Why do you save nbtr.... You’re right. nbtr is reprogrammed by set_bittiming() after reset, so saving/restoring nbtr is redundant. >> + fdbtr = grcan_read_reg(®s->fdbtr); > Who writes fdbtr in the first place? These configuration values are embedded into the CAN controller IP at SoC design time(cfg record). From the driver's standpoint, saving/restoring fdbtr also redundant. -- BR, Arun Muthusamy Software Engineer Frontgrade Gaisler T : +46 (0) 700 558 528 arun.muthusamy@gaisler.com Frontgrade Gaisler AB, Kungsgatan 12, SE-411 19 GÖTEBORG, Sweden. +46 (0) 31 775 8650, www.gaisler.com