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Date:   Thu, 8 Aug 2019 13:49:59 +0200
From:   Maciej Fijalkowski <maciejromanfijalkowski@gmail.com>
To:     Hayes Wang <hayeswang@realtek.com>
Cc:     Jakub Kicinski <jakub.kicinski@netronome.com>,
        "netdev@vger.kernel.org" <netdev@vger.kernel.org>,
        nic_swsd <nic_swsd@realtek.com>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        "linux-usb@vger.kernel.org" <linux-usb@vger.kernel.org>
Subject: Re: [PATCH net-next 5/5] r8152: change rx_frag_head_sz and
 rx_max_agg_num dynamically
Message-ID: <20190808134959.00006a58@gmail.com>
In-Reply-To: <0835B3720019904CB8F7AA43166CEEB2F18D0D8E@RTITMBSVM03.realtek.com.tw>
References: <1394712342-15778-289-albertk@realtek.com>
        <1394712342-15778-294-albertk@realtek.com>
        <20190806151007.75a8dd2c@cakuba.netronome.com>
        <0835B3720019904CB8F7AA43166CEEB2F18D0D8E@RTITMBSVM03.realtek.com.tw>
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On Thu, 8 Aug 2019 08:52:51 +0000
Hayes Wang <hayeswang@realtek.com> wrote:

> Jakub Kicinski [mailto:jakub.kicinski@netronome.com]
> > Sent: Wednesday, August 07, 2019 6:10 AM  
> [...]
> > On Tue, 6 Aug 2019 19:18:04 +0800, Hayes Wang wrote:  
> > > Let rx_frag_head_sz and rx_max_agg_num could be modified dynamically
> > > through the sysfs.
> > >
> > > Signed-off-by: Hayes Wang <hayeswang@realtek.com>  
> > 
> > Please don't expose those via sysfs. Ethtool's copybreak and descriptor
> > count should be applicable here, I think.  
> 
> Excuse me again.
> I find the kernel supports the copybreak of Ethtool.
> However, I couldn't find a command of Ethtool to use it.

Ummm there's set_tunable ops. Amazon's ena driver is making use of it from what
I see. Look at ena_set_tunable() in
drivers/net/ethernet/amazon/ena/ena_ethtool.c.

Maciej

> Do I miss something?
> 
> Best Regards,
> Hayes
>