On Mon, 2016-10-31 at 01:08 +0100, Matthias Brugger wrote: > Hi James, > > On 10/20/2016 10:56 AM, James Liao wrote: > > Some power domain comsumers may init before module_init. > > So the power domain provider (scpsys) need to be initialized > > earlier too. > > > > Take an example for our IOMMU (M4U) and SMI. SMI is a bridge > > between IOMMU and multimedia HW. SMI is responsible to > > enable/disable iommu and help transfer data for each multimedia > > HW. Both of them have to wait until the power and clocks are > > enabled. > > > > So scpsys driver should be initialized before SMI, and SMI should > > be initialized before IOMMU, and then init IOMMU consumers > > (display/vdec/venc/camera etc.). > > > > IOMMU is subsys_init by default. So we need to init scpsys driver > > before subsys_init. > > > > Signed-off-by: James Liao <jamesjj.liao@xxxxxxxxxxxx> > > Reviewed-by: Kevin Hilman <khilman@xxxxxxxxxxxx> > > --- > > I didn't applied this patch for now. > I answered you in v7 of this series [1]. I would prefer to see if we can > fix that otherwise. > > Would be great if you or Yong could provide some feedback. > > Thanks, > Matthias > > [1] https://patchwork.kernel.org/patch/9397405/ > > > drivers/soc/mediatek/mtk-scpsys.c | 19 ++++++++++++++++++- > > 1 file changed, 18 insertions(+), 1 deletion(-) > > > > diff --git a/drivers/soc/mediatek/mtk-scpsys.c b/drivers/soc/mediatek/mtk-scpsys.c > > index fa9ee69..dd7a07d 100644 > > --- a/drivers/soc/mediatek/mtk-scpsys.c > > +++ b/drivers/soc/mediatek/mtk-scpsys.c > > @@ -613,4 +613,21 @@ static int scpsys_probe(struct platform_device *pdev) > > .of_match_table = of_match_ptr(of_scpsys_match_tbl), > > }, > > }; > > -builtin_platform_driver(scpsys_drv); > > + > > +static int __init scpsys_drv_init(void) > > +{ > > + return platform_driver_register(&scpsys_drv); > > +} > > + > > +/* > > + * There are some Mediatek drivers which depend on the power domain driver need > > + * to probe in earlier initcall levels. So scpsys driver also need to probe > > + * earlier. > > + * > > + * IOMMU(M4U) and SMI drivers for example. SMI is a bridge between IOMMU and > > + * multimedia HW. IOMMU depends on SMI, and SMI is a power domain consumer, > > + * so the proper probe sequence should be scpsys -> SMI -> IOMMU driver. > > + * IOMMU drivers are initialized during subsys_init by default, so we need to > > + * move SMI and scpsys drivers to subsys_init or earlier init levels. > > + */ > > +subsys_initcall(scpsys_drv_init); > > Hi Matthias, I got it, thanks. Hi Yong, Is this patch still needed on latest kernel for IOMMU driver? Or we have other solutions for IOMMU driver init? Best regards, James -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
