RE: [PATCH v2] usb: ehci: handshake CMD_RUN instead of STS_HALT

[Neal Liu]

> -----Original Message-----
> From: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx>
> Sent: Thursday, September 2, 2021 12:41 AM
> To: Neal Liu <neal_liu@xxxxxxxxxxxxxx>
> Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>; Tony Prisk
> <linux@xxxxxxxxxxxxxxx>; linux-usb@xxxxxxxxxxxxxxx;
> linux-kernel@xxxxxxxxxxxxxxx; linux-arm-kernel@xxxxxxxxxxxxxxxxxxx; Tao Ren
> <rentao.bupt@xxxxxxxxx>; BMC-SW <BMC-SW@xxxxxxxxxxxxxx>
> Subject: Re: [PATCH v2] usb: ehci: handshake CMD_RUN instead of STS_HALT
> 
> On Wed, Sep 01, 2021 at 11:50:41AM +0800, neal_liu wrote:
> > Retitle.
> >
> > For Aspeed, HCHalted status depends on not only Run/Stop but also
> > ASS/PSS status.
> > Handshake CMD_RUN on startup instead.
> >
> > Signed-off-by: neal_liu <neal_liu@xxxxxxxxxxxxxx>
> 
> I'm still a little doubtful about doing this, but if you guys say it works for your
> hardware then I guess it's okay.
> 
> Acked-by: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx>
 
Thanks for your review.

> > ---
> >  drivers/usb/host/ehci-hcd.c      | 11 ++++++++++-
> >  drivers/usb/host/ehci-platform.c |  6 ++++++
> >  drivers/usb/host/ehci.h          |  1 +
> >  3 files changed, 17 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/usb/host/ehci-hcd.c b/drivers/usb/host/ehci-hcd.c
> > index 10b0365f3439..01c022e46aa2 100644
> > --- a/drivers/usb/host/ehci-hcd.c
> > +++ b/drivers/usb/host/ehci-hcd.c
> > @@ -634,7 +634,16 @@ static int ehci_run (struct usb_hcd *hcd)
> >  	/* Wait until HC become operational */
> >  	ehci_readl(ehci, &ehci->regs->command);	/* unblock posted writes */
> >  	msleep(5);
> > -	rc = ehci_handshake(ehci, &ehci->regs->status, STS_HALT, 0, 100 * 1000);
> > +
> > +	/* For Aspeed, STS_HALT also depends on ASS/PSS status.
> > +	 * Skip this check on startup.
> > +	 */
> > +	if (ehci->is_aspeed)
> > +		rc = ehci_handshake(ehci, &ehci->regs->command, CMD_RUN,
> > +				    1, 100 * 1000);
> > +	else
> > +		rc = ehci_handshake(ehci, &ehci->regs->status, STS_HALT,
> > +				    0, 100 * 1000);
> >
> >  	up_write(&ehci_cf_port_reset_rwsem);
> >
> > diff --git a/drivers/usb/host/ehci-platform.c
> > b/drivers/usb/host/ehci-platform.c
> > index c70f2d0b4aaf..c3dc906274d9 100644
> > --- a/drivers/usb/host/ehci-platform.c
> > +++ b/drivers/usb/host/ehci-platform.c
> > @@ -297,6 +297,12 @@ static int ehci_platform_probe(struct
> platform_device *dev)
> >  					  "has-transaction-translator"))
> >  			hcd->has_tt = 1;
> >
> > +		if (of_device_is_compatible(dev->dev.of_node,
> > +					    "aspeed,ast2500-ehci") ||
> > +		    of_device_is_compatible(dev->dev.of_node,
> > +					    "aspeed,ast2600-ehci"))
> > +			ehci->is_aspeed = 1;
> > +
> >  		if (soc_device_match(quirk_poll_match))
> >  			priv->quirk_poll = true;
> >
> > diff --git a/drivers/usb/host/ehci.h b/drivers/usb/host/ehci.h index
> > 80bb823aa9fe..fdd073cc053b 100644
> > --- a/drivers/usb/host/ehci.h
> > +++ b/drivers/usb/host/ehci.h
> > @@ -219,6 +219,7 @@ struct ehci_hcd {			/* one per controller */
> >  	unsigned		need_oc_pp_cycle:1; /* MPC834X port power */
> >  	unsigned		imx28_write_fix:1; /* For Freescale i.MX28 */
> >  	unsigned		spurious_oc:1;
> > +	unsigned		is_aspeed:1;
> >
> >  	/* required for usb32 quirk */
> >  	#define OHCI_CTRL_HCFS          (3 << 6)
> > --
> > 2.17.1
> >