From mboxrd@z Thu Jan 1 00:00:00 1970 From: Lucas Stach Subject: Re: [PATCH] soc: imx6qp: Use GENPD_FLAG_ALWAYS_ON for PU errata Date: Fri, 13 Jul 2018 12:29:26 +0200 Message-ID: <1531477766.3163.80.camel@pengutronix.de> References: Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8bit Return-path: In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org To: Leonard Crestez , Shawn Guo , Ulf Hansson Cc: "Rafael J. Wysocki" , Fabio Estevam , Robin Gong , Anson Huang , Dong Aisheng , linux-pm@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-imx@nxp.com, kernel@pengutronix.de List-Id: linux-pm@vger.kernel.org Am Freitag, den 13.07.2018, 13:01 +0300 schrieb Leonard Crestez: > This is functionally identical but simpler and slightly faster. > > The PU domain is turned on at boot time and never turned off. In the > current implementation the pm core will repeatedly call power_off when > the domain is unused and get -EBUSY back. If the domain is marked as > "always on" instead the pm core won't even attempt to turn it off. > > In theory on 6qp it is safe to turn PU off in suspend, however that is > best accomplished with a new core flag. > > Signed-off-by: Leonard Crestez Reviewed-by: Lucas Stach > --- >  drivers/soc/imx/gpc.c | 8 ++------ >  1 file changed, 2 insertions(+), 6 deletions(-) > > Previous discussion: > * https://lkml.org/lkml/2018/7/11/431 > * https://lkml.org/lkml/2018/7/10/103 > > Attempt at turning PU off in suspend: > * https://lkml.org/lkml/2018/7/6/698 > > diff --git a/drivers/soc/imx/gpc.c b/drivers/soc/imx/gpc.c > index faf13a0b85d6..f31978e5af20 100644 > --- a/drivers/soc/imx/gpc.c > +++ b/drivers/soc/imx/gpc.c > @@ -45,11 +45,10 @@ struct imx_pm_domain { > >   struct clk *clk[GPC_CLK_MAX]; > >   int num_clks; > >   unsigned int reg_offs; > >   signed char cntr_pdn_bit; > >   unsigned int ipg_rate_mhz; > > - unsigned int flags; >  }; >   >  static inline struct imx_pm_domain * >  to_imx_pm_domain(struct generic_pm_domain *genpd) >  { > @@ -60,13 +59,10 @@ static int imx6_pm_domain_power_off(struct generic_pm_domain *genpd) >  { > >   struct imx_pm_domain *pd = to_imx_pm_domain(genpd); > >   int iso, iso2sw; > >   u32 val; >   > > - if (pd->flags & PGC_DOMAIN_FLAG_NO_PD) > > - return -EBUSY; > - > >   /* Read ISO and ISO2SW power down delays */ > >   regmap_read(pd->regmap, pd->reg_offs + GPC_PGC_PUPSCR_OFFS, &val); > >   iso = val & 0x3f; > >   iso2sw = (val >> 8) & 0x3f; >   > @@ -419,12 +415,12 @@ static int imx_gpc_probe(struct platform_device *pdev) > >   return ret; > >   } >   > >   /* Disable PU power down in normal operation if ERR009619 is present */ > >   if (of_id_data->err009619_present) > > - imx_gpc_domains[GPC_PGC_DOMAIN_PU].flags |= > > - PGC_DOMAIN_FLAG_NO_PD; > > + imx_gpc_domains[GPC_PGC_DOMAIN_PU].base.flags |= > > + GENPD_FLAG_ALWAYS_ON; >   > >   /* Keep DISP always on if ERR006287 is present */ > >   if (of_id_data->err006287_present) > >   imx_gpc_domains[GPC_PGC_DOMAIN_DISPLAY].base.flags |= > >   GENPD_FLAG_ALWAYS_ON;