From: "Westergreen, Dalon" <dalon.westergreen@intel.com>
To: "kuba@kernel.org" <kuba@kernel.org>
Cc: "mkubecek@suse.cz" <mkubecek@suse.cz>,
"davem@davemloft.net" <davem@davemloft.net>,
"Tan, Ley Foon" <ley.foon.tan@intel.com>,
"See, Chin Liang" <chin.liang.see@intel.com>,
"Nguyen, Dinh" <dinh.nguyen@intel.com>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"netdev@vger.kernel.org" <netdev@vger.kernel.org>,
"Ooi, Joyce" <joyce.ooi@intel.com>,
"thor.thayer@linux.intel.com" <thor.thayer@linux.intel.com>
Subject: Re: [PATCH v4 09/10] net: eth: altera: add msgdma prefetcher
Date: Tue, 14 Jul 2020 18:51:15 +0000 [thread overview]
Message-ID: <9a8ba2616f72fb44cdc3b45fabfb4d7bdf961fd0.camel@intel.com> (raw)
In-Reply-To: <20200714092903.38581b74@kicinski-fedora-pc1c0hjn.dhcp.thefacebook.com>
On Tue, 2020-07-14 at 09:29 -0700, Jakub Kicinski wrote:
> On Tue, 14 Jul 2020 15:58:53 +0000 Westergreen, Dalon wrote:
> > On Tue, 2020-07-14 at 08:55 -0700, Jakub Kicinski wrote:
> > > On Tue, 14 Jul 2020 14:35:16 +0000 Ooi, Joyce wrote:
> > > > > I'm no device tree expert but these look like config options rather
> > > > > than
> > > > > HW
> > > > > description. They also don't appear to be documented in the next
> > > > > patch.
> > > >
> > > > The poll_freq are part of the msgdma prefetcher IP, whereby it
> > > > specifies the frequency of descriptor polling operation. I can add
> > > > the poll_freq description in the next patch.
> > >
> > > Is the value decided at the time of synthesis or can the driver choose
> > > the value it wants?
> >
> > It is not controlled at synthesis, this parameter should likely not be a
> > devicetree parameter, perhaps just make it a module parameter with a default
> > value.
>
> Let's see if I understand the feature - instead of using a doorbell the
> HW periodically checks the contents of the next-to-use descriptor to
> see if it contains a valid tx frame or rx buffer?
>
Yes, it checks the next-to-use descriptor to see if the descriptor is valid.
the value specifies the number of cycles to wait before checking again
> I've seen vendors abuse fields of ethtool --coalesce to configure
> similar settings. tx-usecs-irq and rx-usecs-irq, I think. Since this
> part of ethtool API has been ported to netlink, could we perhaps add
> a new field to ethtool --coalesce?
I don't think this is necessary, i think just having a module parameter
meets our needs. I don't see a need for the value to change on a per
interface basis. This was primarily used during testing / bringup.
-dalon
next prev parent reply other threads:[~2020-07-14 19:07 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-08 7:23 [PATCH v4 00/10] net: eth: altera: tse: Add PTP and mSGDMA prefetcher Ooi, Joyce
2020-07-08 7:23 ` [PATCH v4 01/10] net: eth: altera: tse_start_xmit ignores tx_buffer call response Ooi, Joyce
2020-07-23 16:32 ` Thor Thayer
2020-07-08 7:23 ` [PATCH v4 02/10] net: eth: altera: set rx and tx ring size before init_dma call Ooi, Joyce
2020-07-23 16:33 ` Thor Thayer
2020-07-08 7:23 ` [PATCH v4 03/10] net: eth: altera: fix altera_dmaops declaration Ooi, Joyce
2020-07-23 16:33 ` Thor Thayer
2020-07-08 7:23 ` [PATCH v4 04/10] net: eth: altera: add optional function to start tx dma Ooi, Joyce
2020-07-23 16:35 ` Thor Thayer
2020-07-08 7:23 ` [PATCH v4 05/10] net: eth: altera: Move common functions to altera_utils Ooi, Joyce
2020-07-23 16:39 ` Thor Thayer
2020-07-08 7:23 ` [PATCH v4 06/10] net: eth: altera: Add missing identifier names to function declarations Ooi, Joyce
2020-07-23 16:40 ` Thor Thayer
2020-07-08 7:23 ` [PATCH v4 07/10] net: eth: altera: change tx functions to type netdev_tx_t Ooi, Joyce
2020-07-23 16:41 ` Thor Thayer
2020-07-08 7:23 ` [PATCH v4 08/10] net: eth: altera: add support for ptp and timestamping Ooi, Joyce
2020-07-09 11:31 ` Richard Cochran
2020-07-15 3:48 ` Ooi, Joyce
2020-07-23 17:05 ` Thor Thayer
2020-07-08 7:24 ` [PATCH v4 09/10] net: eth: altera: add msgdma prefetcher Ooi, Joyce
2020-07-08 17:33 ` David Miller
2020-07-14 14:36 ` Ooi, Joyce
2020-07-08 21:49 ` Jakub Kicinski
2020-07-14 14:35 ` Ooi, Joyce
2020-07-14 15:55 ` Jakub Kicinski
2020-07-14 15:58 ` Westergreen, Dalon
2020-07-14 16:29 ` Jakub Kicinski
2020-07-14 18:51 ` Westergreen, Dalon [this message]
2020-07-14 19:13 ` Jakub Kicinski
2020-07-14 20:23 ` David Miller
2020-07-14 23:25 ` Westergreen, Dalon
2020-07-08 7:24 ` [PATCH v4 10/10] net: eth: altera: update devicetree bindings documentation Ooi, Joyce
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