From: Grygorii Strashko <grygorii.strashko@ti.com>
To: Ivan Khoronzhuk <ivan.khoronzhuk@linaro.org>
Cc: "David S. Miller" <davem@davemloft.net>, <netdev@vger.kernel.org>,
Mugunthan V N <mugunthanvnm@ti.com>, Sekhar Nori <nsekhar@ti.com>,
<linux-kernel@vger.kernel.org>, <linux-omap@vger.kernel.org>
Subject: Re: [PATCH 5/7] Documentation: DT: net: cpsw: allow to specify descriptors pool size
Date: Wed, 7 Dec 2016 13:41:49 -0600 [thread overview]
Message-ID: <30905e3e-d44f-e1f1-a22a-226b9ea53868@ti.com> (raw)
In-Reply-To: <23737800-cca5-fbd4-e21c-5430ecf7ab34@ti.com>
On 12/02/2016 11:21 AM, Grygorii Strashko wrote:
>
>
> On 12/02/2016 05:28 AM, Ivan Khoronzhuk wrote:
>> On Thu, Dec 01, 2016 at 05:34:30PM -0600, Grygorii Strashko wrote:
>>> Add optional property "descs_pool_size" to specify buffer descriptor's
>>> pool size. The "descs_pool_size" should define total number of CPDMA
>>> CPPI descriptors to be used for both ingress/egress packets
>>> processing. If not specified - the default value 256 will be used
>>> which will allow to place descriptor's pool into the internal CPPI
>>> RAM on most of TI SoC.
>>>
>>> Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>
>>> ---
>>> Documentation/devicetree/bindings/net/cpsw.txt | 5 +++++
>>> 1 file changed, 5 insertions(+)
>>>
>>> diff --git a/Documentation/devicetree/bindings/net/cpsw.txt b/Documentation/devicetree/bindings/net/cpsw.txt
>>> index 5ad439f..b99d196 100644
>>> --- a/Documentation/devicetree/bindings/net/cpsw.txt
>>> +++ b/Documentation/devicetree/bindings/net/cpsw.txt
>>> @@ -35,6 +35,11 @@ Optional properties:
>>> For example in dra72x-evm, pcf gpio has to be
>>> driven low so that cpsw slave 0 and phy data
>>> lines are connected via mux.
>>> +- descs_pool_size : total number of CPDMA CPPI descriptors to be used for
>>> + both ingress/egress packets processing. if not
>>> + specified the default value 256 will be used which
>>> + will allow to place descriptors pool into the
>>> + internal CPPI RAM.
>> Does it describe h/w? Why now module parameter? or even smth like ethtool num
>> ring entries?
>>
>
> It can be module parameter too. for the use cases i'm aware of -
> this is one-time boot setting only.
>
> ----- OR
> So, do you propose to use
> ethtool -g ethX
>
> ethtool -G ethX [rx N] [tx N]
> ?
>
> Now cpdma has one pool for all RX/TX channels, so changing this settings
> by ethtool will require: pause interfaces, reallocate cpdma pool,
> re-arrange buffers between channels, resume interface. Correct?
>
> How do you think - we can move forward with one pool or better to have two (Rx and Tx)?
>
> Wouldn't it be reasonable to still have DT (or module) parameter to avoid
> cpdma reconfiguration on system startup (pause/resume interfaces) (faster boot)?
>
> How about cpdma re-allocation policy (with expectation that is shouldn't happen too often)?
> - increasing of Rx, Tx will grow total number of physically allocated buffers (total_desc_num)
> - decreasing of Rx, Tx will just change number of available buffers (no memory re-allocation)
>
> ----- OR ----
> Can we move forward with current patch (total number of CPDMA CPPI descriptors defined in DT)
> and add ethtool -G ethX [rx N] [tx N] which will allow to re-split descs between RX and TX?
>
>
if no comments here, I'll rework patches to use module parameter for descs_pool_size and
will add possibility to re-split RX/TX buffers using ethtool -G ethX [rx N] [tx N]
--
regards,
-grygorii
next prev parent reply other threads:[~2016-12-07 19:41 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-12-01 23:34 [PATCH 0/7] net: ethernet: ti: cpsw: support placing CPDMA descriptors into DDR Grygorii Strashko
2016-12-01 23:34 ` [PATCH 1/7] net: ethernet: ti: cpdma: am437x: allow descs to be plased in ddr Grygorii Strashko
2016-12-03 20:34 ` David Miller
2016-12-05 17:57 ` Grygorii Strashko
2016-12-01 23:34 ` [PATCH 2/7] net: ethernet: ti: cpdma: fix desc re-queuing Grygorii Strashko
2016-12-02 11:03 ` Ivan Khoronzhuk
2016-12-02 16:45 ` Grygorii Strashko
2016-12-02 23:28 ` Ivan Khoronzhuk
2016-12-05 18:22 ` Grygorii Strashko
2016-12-01 23:34 ` [PATCH 3/7] net: ethernet: ti: cpdma: minimize number of parameters in cpdma_desc_pool_create/destroy() Grygorii Strashko
2016-12-01 23:34 ` [PATCH 4/7] net: ethernet: ti: cpdma: use devm_ioremap Grygorii Strashko
2016-12-01 23:34 ` [PATCH 5/7] Documentation: DT: net: cpsw: allow to specify descriptors pool size Grygorii Strashko
2016-12-02 11:28 ` Ivan Khoronzhuk
2016-12-02 17:21 ` Grygorii Strashko
2016-12-07 19:41 ` Grygorii Strashko [this message]
2016-12-02 17:22 ` Grygorii Strashko
2016-12-03 0:37 ` Ivan Khoronzhuk
2016-12-01 23:34 ` [PATCH 6/7] net: ethernet: ti: cpsw: add support for descs_pool_size dt property Grygorii Strashko
2016-12-01 23:34 ` [PATCH 7/7] Documentation: DT: net: cpsw: remove no_bd_ram property Grygorii Strashko
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