Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965828AbcKJTwb (ORCPT ); Thu, 10 Nov 2016 14:52:31 -0500 Received: from mail-lf0-f44.google.com ([209.85.215.44]:35367 "EHLO mail-lf0-f44.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S935930AbcKJTw3 (ORCPT ); Thu, 10 Nov 2016 14:52:29 -0500 From: "ivan.khoronzhuk" X-Google-Original-From: "ivan.khoronzhuk" Subject: Re: [PATCH] net: ethernet: ti: davinci_cpdma: fix fixed prio cpdma ctlr configuration To: Grygorii Strashko , Ivan Khoronzhuk , mugunthanvnm@ti.com, netdev@vger.kernel.org References: <1478610656-24634-1-git-send-email-ivan.khoronzhuk@linaro.org> <592966c0-ae4c-ba6b-43ba-8ca837e9a700@linaro.org> <37548a54-c54b-3194-691a-22fa8118ed3d@ti.com> Cc: linux-omap@vger.kernel.org, linux-kernel@vger.kernel.org Message-ID: <1501d6bd-ef97-cfb4-f02b-2b03b97ae636@globallogic.com> Date: Thu, 10 Nov 2016 21:52:24 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.4.0 MIME-Version: 1.0 In-Reply-To: <37548a54-c54b-3194-691a-22fa8118ed3d@ti.com> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3663 Lines: 107 On 10.11.16 18:37, Grygorii Strashko wrote: > > > On 11/09/2016 05:56 PM, Ivan Khoronzhuk wrote: >> >> >> On 09.11.16 23:09, Grygorii Strashko wrote: >>> >>> >>> On 11/08/2016 07:10 AM, Ivan Khoronzhuk wrote: >>>> The dma ctlr is reseted to 0 while cpdma start, thus cpdma ctlr >>> >>> I assume this is because cpdma_ctlr_start() does soft reset. Is it >>> correct? >> Probably not. I've seen this register doesn't hold any previous settings >> (just trash) > > What register CPDMA_DMACONTROL or CPSW_DMACTRL? > >> after cpdma_ctlr_stop(), actually after last channel is stopped (inside >> of cpdma_ctlr_stop()). > > So, You are stating that Registers context is changed after stop? > >> Then cpdma_ctlr_start() just reset it to 0. > > "just trash" or "0". > > Sry, I do not see how cpdma_ctlr_stop() can affect on registers state :( > and I'd very appreciated if can provide more detailed information. > I've checked again, it was my mistake. It simply reset to 0 while soft reset. >> >>> >>>> cannot be configured after cpdma is stopped. So, restore content >>>> of cpdma ctlr while off/on procedure. >>>> >>>> Based on net-next/master >>> >>> ^ remove it >> sure >> >>> >>>> >>>> Signed-off-by: Ivan Khoronzhuk >>>> --- >>>> drivers/net/ethernet/ti/cpsw.c | 6 +- >>>> drivers/net/ethernet/ti/davinci_cpdma.c | 103 >>>> +++++++++++++++++--------------- >>>> drivers/net/ethernet/ti/davinci_cpdma.h | 2 + >>>> 3 files changed, 58 insertions(+), 53 deletions(-) >>>> >>>> diff --git a/drivers/net/ethernet/ti/cpsw.c >>>> b/drivers/net/ethernet/ti/cpsw.c >>>> index b1ddf89..4d04b8e 100644 >>>> --- a/drivers/net/ethernet/ti/cpsw.c >>>> +++ b/drivers/net/ethernet/ti/cpsw.c >>>> @@ -1376,10 +1376,6 @@ static int cpsw_ndo_open(struct net_device *ndev) >>>> ALE_ALL_PORTS, ALE_ALL_PORTS, 0, 0); >>>> >>>> if (!cpsw_common_res_usage_state(cpsw)) { >>>> - /* setup tx dma to fixed prio and zero offset */ >>>> - cpdma_control_set(cpsw->dma, CPDMA_TX_PRIO_FIXED, 1); >>>> - cpdma_control_set(cpsw->dma, CPDMA_RX_BUFFER_OFFSET, 0); >>>> - >>>> /* disable priority elevation */ >>>> __raw_writel(0, &cpsw->regs->ptype); >>>> >>>> @@ -2710,6 +2706,8 @@ static int cpsw_probe(struct platform_device >>>> *pdev) >>>> dma_params.desc_align = 16; >>>> dma_params.has_ext_regs = true; >>>> dma_params.desc_hw_addr = dma_params.desc_mem_phys; >>>> + dma_params.rxbuf_offset = 0; >>>> + dma_params.fixed_prio = 1; >>> >>> Do we really need this new parameters? Do you have plans to use other >>> values? >> I'm ok if this is static (equally as a bunch of rest in dma_params), no >> see reason to use other values, > > That's what i wanted to know :) - go static, pls. > >> it at least now. But the issue is not only in these two parameters and >> not only in cpsw_ndo_open(). >> It touches cpsw_set_channels() also, where ctlr stop/start is present. >> In order to not copy cpdma_control_set(cpsw->dma, CPDMA_TX_PRIO_FIXED, >> 1)... >> in all such kind places in eth drivers, better to allow the cpdma to >> control it's parameters... >> >> The cpdma ctlr register holds a little more parameters (but only two of >> them are set in cpsw) >> Maybe there is reason to save them also. Actually I'd seen this problem >> when playing with >> on/off channel shapers, unfortunately the cpdma ctlr holds this info >> also, and it was lost >> while on/off (but I'm going to restore it in chan_start()). >> > > I understand you change, but I'm note sure about real root cause :( so, are you Ok with current version? >