From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754271AbeDTDt7 (ORCPT ); Thu, 19 Apr 2018 23:49:59 -0400 Received: from mailgw02.mediatek.com ([210.61.82.184]:15958 "EHLO mailgw02.mediatek.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1754155AbeDTDt5 (ORCPT ); Thu, 19 Apr 2018 23:49:57 -0400 X-UUID: ccbf26155af945d7b24ce3fef72de5e8-20180420 Message-ID: <1524196190.26454.3.camel@mtkswgap22> Subject: Re: [PATCH v1 5/7] soc: mediatek: add a fixed wait for SRAM stable From: Sean Wang To: Matthias Brugger CC: , , , , , , , , , "Ulf Hansson" , Weiyi Lu Date: Fri, 20 Apr 2018 11:49:50 +0800 In-Reply-To: <5f2530a0-aee2-39fe-eb5c-56cd4a68c9db@gmail.com> References: <0fc10b2498c6dbe20141831c722c32cc74330d3d.1522736996.git.sean.wang@mediatek.com> <5f2530a0-aee2-39fe-eb5c-56cd4a68c9db@gmail.com> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.2.3-0ubuntu6 Content-Transfer-Encoding: 7bit MIME-Version: 1.0 X-MTK: N Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 2018-04-19 at 12:33 +0200, Matthias Brugger wrote: > > On 04/03/2018 09:15 AM, sean.wang@mediatek.com wrote: > > From: Sean Wang > > > > MT7622_POWER_DOMAIN_WB doesn't send an ACK when its managed SRAM becomes > > stable, which is not like the behavior the other power domains should > > have. Therefore, it's necessary for such a power domain to have a fixed > > and well-predefined duration to wait until its managed SRAM can be allowed > > to access by all functions running on the top. > > > > Signed-off-by: Sean Wang > > Cc: Matthias Brugger > > Cc: Ulf Hansson > > Cc: Weiyi Lu > > --- > > drivers/soc/mediatek/mtk-scpsys.c | 17 ++++++++++++----- > > 1 file changed, 12 insertions(+), 5 deletions(-) > > > > diff --git a/drivers/soc/mediatek/mtk-scpsys.c b/drivers/soc/mediatek/mtk-scpsys.c > > index f9b7248..19aceb8 100644 > > --- a/drivers/soc/mediatek/mtk-scpsys.c > > +++ b/drivers/soc/mediatek/mtk-scpsys.c > > @@ -121,6 +121,7 @@ struct scp_domain_data { > > u32 bus_prot_mask; > > enum clk_id clk_id[MAX_CLKS]; > > bool active_wakeup; > > + u32 us_sram_fwait; > > Before adding more and more fields to scp_domain_data which get checked in if's, > I'd prefer to add a caps field used for bus_prot_mask, active_wakeup in a first > patch and add the cap FORCE_WAIT in a second patch. > > Can you help to implement this Sean, or shall I give it a try? > Sure, I have a willing to do and then see if you're also fond of it. thanks! > Regards, > Matthias > > > }; > > > > struct scp; > > @@ -234,11 +235,16 @@ static int scpsys_power_on(struct generic_pm_domain *genpd) > > val &= ~scpd->data->sram_pdn_bits; > > writel(val, ctl_addr); > > > > - /* wait until SRAM_PDN_ACK all 0 */ > > - ret = readl_poll_timeout(ctl_addr, tmp, (tmp & pdn_ack) == 0, > > - MTK_POLL_DELAY_US, MTK_POLL_TIMEOUT); > > - if (ret < 0) > > - goto err_pwr_ack; > > + /* Either wait until SRAM_PDN_ACK all 0 or have a force wait */ > > + if (!scpd->data->us_sram_fwait) { > > + ret = readl_poll_timeout(ctl_addr, tmp, (tmp & pdn_ack) == 0, > > + MTK_POLL_DELAY_US, MTK_POLL_TIMEOUT); > > + if (ret < 0) > > + goto err_pwr_ack; > > + } else { > > + usleep_range(scpd->data->us_sram_fwait, > > + scpd->data->us_sram_fwait + 100); > > + }; > > > > if (scpd->data->bus_prot_mask) { > > ret = mtk_infracfg_clear_bus_protection(scp->infracfg, > > @@ -783,6 +789,7 @@ static const struct scp_domain_data scp_domain_data_mt7622[] = { > > .clk_id = {CLK_NONE}, > > .bus_prot_mask = MT7622_TOP_AXI_PROT_EN_WB, > > .active_wakeup = true, > > + .us_sram_fwait = 12000, > > }, > > }; > > > >