Messages in this thread | | | From | Ulf Hansson <> | Date | Tue, 10 Jul 2018 00:33:21 +0200 | Subject | Re: [PATCH v2 1/2] soc: imx: gpc: Disable 6sl display power gating for ERR006287 |
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On 9 July 2018 at 14:23, Leonard Crestez <leonard.crestez@nxp.com> wrote: > The imx6sl chip errata document describes ERR006287 like this: > > """ > Upon resuming from power gating, the modules in the display power domain > (eLCDIF, EPDC, PXP and SPDC) might fail to perform register reads > correctly. > > When the modules listed above are used, do not use power gating on the > display power domain. > """ > > Link: https://www.nxp.com/docs/en/errata/IMX6SLCE.pdf#page=62 > > Handle this in linux in the same way as imx6qp ERR009619: make the DISP > domain return -EBUSY on power_off. > > Signed-off-by: Leonard Crestez <leonard.crestez@nxp.com> > --- > drivers/soc/imx/gpc.c | 10 ++++++++++ > 1 file changed, 10 insertions(+) > > diff --git a/drivers/soc/imx/gpc.c b/drivers/soc/imx/gpc.c > index 526f2d02dc78..6b726dada560 100644 > --- a/drivers/soc/imx/gpc.c > +++ b/drivers/soc/imx/gpc.c > @@ -339,30 +339,35 @@ static struct imx_pm_domain imx_gpc_domains[] = { > }; > > struct imx_gpc_dt_data { > int num_domains; > bool err009619_present; > + bool err006287_present; > }; > > static const struct imx_gpc_dt_data imx6q_dt_data = { > .num_domains = 2, > .err009619_present = false, > + .err006287_present = false, > }; > > static const struct imx_gpc_dt_data imx6qp_dt_data = { > .num_domains = 2, > .err009619_present = true, > + .err006287_present = false, > }; > > static const struct imx_gpc_dt_data imx6sl_dt_data = { > .num_domains = 3, > .err009619_present = false, > + .err006287_present = true, > }; > > static const struct imx_gpc_dt_data imx6sx_dt_data = { > .num_domains = 4, > .err009619_present = false, > + .err006287_present = false, > }; > > static const struct of_device_id imx_gpc_dt_ids[] = { > { .compatible = "fsl,imx6q-gpc", .data = &imx6q_dt_data }, > { .compatible = "fsl,imx6qp-gpc", .data = &imx6qp_dt_data }, > @@ -467,10 +472,15 @@ static int imx_gpc_probe(struct platform_device *pdev) > /* 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; > > + /* Disable DISP power down in normal operation if ERR006287 is present */ > + if (of_id_data->err006287_present) > + imx_gpc_domains[GPC_PGC_DOMAIN_DISPLAY].flags |= > + PGC_DOMAIN_FLAG_NO_PD; > +
This looks like a use-case for an always powered on PM domain?
If that's the case, GENPD_FLAG_ALWAYS_ON does the trick, but more efficient as it enables genpd to take a few shortcuts when trying to power of a PM domain.
> if (!pgc_node) { > ret = imx_gpc_old_dt_init(&pdev->dev, regmap, > of_id_data->num_domains); > if (ret) > return ret; > -- > 2.17.1 >
Kind regards Uffe
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