On Wed, Feb 27, 2013 at 02:12:38PM +0200, Felipe Balbi wrote:

Hi,

On Wed, Feb 27, 2013 at 10:22:03AM +0800, Peter Chen wrote:

quoted

On Tue, Feb 26, 2013 at 11:42:34AM +0200, Felipe Balbi wrote:

quoted

On Sun, Feb 17, 2013 at 05:24:42PM +0800, Peter Chen wrote:

quoted

If the probe fails, the ci13xxx_add_device will not return error,
(bus_probe_device doesn't has return value)
therefore, the platform layer can't know whether core's probe
is successful or not, if platform layer goes on using core's struct
which is initialized at core's probe, the error will occur.

This error is showed when I only compile gadget, the host-only
controller reports "no supported roles", and fails probe, but imx
platform code doesn't know it, and goes on using core's private data.

Signed-off-by: Peter Chen <redacted>

this just tells you that platform code shouldn't be using the driver
directly. passing probe_retval via platform_data is an abomination, fix
the real problem instead, whatever it is.

So you suggest the platform glue layer should not use core driver's data
directly, eg, for your dwc3, the platform glue layer should not use
struct dwc3 *dwc directly? 

yes, and it doesn't. Ever.

quoted

At dwc3-exynos.c,  it has code "exynos->dwc3    = dwc3;", so the exynos
platform code may will use struct dwc3 in future. Besides, if the dwc3

nonsense. That's a structure platform_device which was created by the
glue, it has nothing to do with struct dwc3. struct platform_device
belongs to the glue, but there's an easy way to prevent that by using
device_for_each_child() on your ->remove() method.

Sorry, I just thought it may use platform_get_drvdata(exynos->dwc3) to
get core data if exynos has special suspend/resume routine, and need
to visit dwc3 register.

wrong. There's no need for any notification at all. A driver failing to
probe is just normal life. DWC3 is releasing all resources it allocated,
but the glue still needs the clock, then that's just the way it is.

Here, we just talk the controller core clk, if the core fails to probe, 
any meaningful for platform layer still alive?

There are many error messages which will tell the user that e.g. dwc3
failed to probe and user will just try again. If clocks are left
enabled, that's a bug in either core driver or glue layer which needs
fixing.

If the dwc3 core fails to probe, but controller core clk is still on, is it
a valid case?

quoted

core driver as there are many platform specific things, eg, special init/
shutdown, suspend/resume, board layer gpio setting for vbus control (used

gpio handling should be done at board-file, that's a bug. You need to
add a fixed regulator which is toggled by a GPIO.

I think I need to move vbus regulator from platform code to core code as we have
struct otg at core data, and vbus operation is common operation.

-- 
balbi

-- 

Best Regards,
Peter Chen