Hi Aisheng, On Mon, Nov 9, 2020 at 10:57 AM Aisheng Dong <aisheng.d...@nxp.com> wrote: > > Hi Greg, > > > From: Greg Kroah-Hartman <gre...@linuxfoundation.org> > > Sent: Monday, November 9, 2020 6:37 PM > > Subject: Re: [PATCH RESEND] driver core: export device_is_bound() to fix > > build > > failure > > > > On Mon, Nov 09, 2020 at 10:14:46AM +0000, Sudip Mukherjee wrote: > > > Hi Greg, > > > > > > On Sun, Nov 8, 2020 at 8:23 AM Greg Kroah-Hartman > > > <gre...@linuxfoundation.org> wrote: > > > > > > > > On Sat, Nov 07, 2020 at 10:47:27PM +0000, Sudip Mukherjee wrote: > > > > > When CONFIG_MXC_CLK_SCU is configured as 'm' the build fails as it > > > > > is unable to find device_is_bound(). The error being: > > > > > ERROR: modpost: "device_is_bound" [drivers/clk/imx/clk-imx-scu.ko] > > > > > undefined! > > > > > > > > > > Export the symbol so that the module finds it. > > > > >
<snip> > > > > probe() should never call this function as it makes no sense at all at that > > point in > > time. The driver should be fixed. > > Would you suggest if any other API we can use to allow the driver to know > whether > another device has been probed? > > For imx scu driver in question, it has a special requirement that it depends > on scu power domain > driver. However, there're a huge number (200+) of power domains for each > device clock, we can't define > them all in DT for a single clock controller node. > > That's why we wanted to use device_is_bound() before to check if scu power > domain is ready or not to > support defer probe. iiuc, you are waiting for "fsl,scu-pd" to be registered. I think you might be able to use bus_for_each_dev() to check if the device has registered with the bus or not. It will be on the bus only after bind was successful. The bus will be "platform_bus_type". But I am sure Greg can give you better suggestion than this. :) -- Regards Sudip