Return-Path: Message-ID: <1524473894.12322.13.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: Mon, 23 Apr 2018 16:58:14 +0800 In-Reply-To: <1524196190.26454.3.camel@mtkswgap22> References: <0fc10b2498c6dbe20141831c722c32cc74330d3d.1522736996.git.sean.wang@mediatek.com> <5f2530a0-aee2-39fe-eb5c-56cd4a68c9db@gmail.com> <1524196190.26454.3.camel@mtkswgap22> Content-Type: text/plain; charset="UTF-8" MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: On Fri, 2018-04-20 at 11:49 +0800, Sean Wang wrote: > 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! > Hi, Matthias I have done it in [1], but in the version, I doesn't merge bus_prot_mask into caps fields because bus_prot_mask is actually mapped into realistic hardware bitmap like sram_pdn_bits, sram_pdn_ack_bits, sta_mask is doing. It should be more straightforward to port a new SoC to scpsys when there are standalone fields to hold these hardware configuring bitmaps. [1] http://lists.infradead.org/pipermail/linux-mediatek/2018-April/012884.html Sean > > 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, > > > }, > > > }; > > > > > > >