Re: [PATCH v5 2/2] phy: rockchip-inno-usb2: add a new driver for Rockchip usb2phy

[Frank Wang]

Hi Heiko,

On 2016/6/15 17:04, Heiko StÃbner wrote:
> Hi Frank,
>
> Am Mittwoch, 15. Juni 2016, 11:23:26 schrieb Frank Wang:
> > On 2016/6/14 21:27, Heiko StÃbner wrote:
> > > Am Montag, 13. Juni 2016, 10:10:10 schrieb Frank Wang:
> > > > The newer SoCs (rk3366, rk3399) take a different usb-phy IP block
> > > > than rk3288 and before, and most of phy-related registers are also
> > > > different from the past, so a new phy driver is required necessarily.
> > > >
> > > > Signed-off-by: Frank Wang <frank.wang@xxxxxxxxxxxxxx>
> > > > ---
> > > >
> > > > Changes in v5:
> > > >    - Added 'reg' in the data block to match the different phy-blocks in
> > > >    dt.
> > > >
> > > > Changes in v4:
> > > >    - Removed some processes related to 'vbus_host-supply'.
> > > >
> > > > Changes in v3:
> > > >    - Resolved the mapping defect between fixed value in driver and the
> > > >
> > > > property in devicetree.
> > > >
> > > >    - Optimized 480m output clock register function.
> > > >    - Code cleanup.
> > > >
> > > > Changes in v2:
> > > >    - Changed vbus_host operation from gpio to regulator in *_probe.
> > > >    - Improved the fault treatment relate to 480m clock register.
> > > >    - Cleaned up some meaningless codes in *_clk480m_disable.
> > > >    - made more clear the comment of *_sm_work.
> > > >    
> > > >    drivers/phy/Kconfig                  |    7 +
> > > >    drivers/phy/Makefile                 |    1 +
> > > >    drivers/phy/phy-rockchip-inno-usb2.c |  645
> > > >
> > > > ++++++++++++++++++++++++++++++++++ 3 files changed, 653 insertions(+)
> > > >
> > > > [...]
> > > >
> > > > +
> > > > +static int rockchip_usb2phy_exit(struct phy *phy)
> > > > +{
> > > > +	struct rockchip_usb2phy_port *rport = phy_get_drvdata(phy);
> > > > +
> > > 	if (!rport->port_cfg)
> > > 	
> > > 		return 0;
> > > > +	if (rport->port_id == USB2PHY_PORT_HOST)
> > > > +		cancel_delayed_work_sync(&rport->sm_work);
> > > > +
> > > you will also need to resume the port here, if it is suspended at this
> > > point, as phy_power_off gets called after phy_exit and would probably
> > > produce clk enable/disable mismatches otherwise.
> > Hmm, from my personal point of view, when canceling sm_work here, it may
> > not cause the port goes to suspend, isn't it? besides, clk only prepared
> > in *_usb2phy_resume(), and unprepared in *_usb2phy_suspend(), so if we
> > resume port here,  the prepare_count of clk will be increased again, I
> > am afraid this is not correct, and am I wrong? would you like to tell me
> > more details?
> usb2phy_resume gets called both initially through phy_power_on as well.
> So it's on but through the first scheduled work call, might get suspended when
> nothing is connected. (clk_enable and clk_disable will run).
> If nothing is connected on unload phy_power_off will get called while the
> clock actually is still disabled.
>
> So I think it's either resuming on exit, or at least making sure to do nothing
> in that case in the phy_power_off callback of the driver.

Well, I got what you mean. I saw phy_power_on() gets called  twice at 
ehci/ohci driver probe time, one is at pdata->power_on(); another is at 
usb_add_hcd(), so after that, the power_count of phy increases to two. 
however, when ehci/ohci driver goes to suspend, there is only once to 
call phy_power_off(), and the power_count of phy decreases to 1, so our 
usb2phy_resume() could not be invoked :-) .

If so, is it still need to care it? How about use suspended member of 
rockchip_usb2phy_port as a conditional to check in *_usb2phy_suspend(), 
if necessary.

BR.
Frank