| Message ID | 20210826071525.27651-1-neal_liu@aspeedtech.com |
|---|---|
| State | New |
| Headers | show |
| Series | usb: host: ehci: skip STS_HALT check for aspeed platform | expand |
> -----Original Message----- > From: Alan Stern <stern@rowland.harvard.edu> > Sent: Thursday, August 26, 2021 11:28 PM > To: Neal Liu <neal_liu@aspeedtech.com> > Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>; Tony Prisk > <linux@prisktech.co.nz>; linux-usb@vger.kernel.org; > linux-kernel@vger.kernel.org; linux-arm-kernel@lists.infradead.org; Tao Ren > <rentao.bupt@gmail.com>; BMC-SW <BMC-SW@aspeedtech.com> > Subject: Re: [PATCH] usb: host: ehci: skip STS_HALT check for aspeed platform > > On Thu, Aug 26, 2021 at 03:15:25PM +0800, neal_liu wrote: > > STS_HALT also depends on ASS/PSS status for apseed. > > Skip this check on startup. > > > > Signed-off-by: neal_liu <neal_liu@aspeedtech.com> > > --- > > drivers/usb/host/ehci-hcd.c | 10 +++++++++- > > drivers/usb/host/ehci-platform.c | 6 ++++++ > > drivers/usb/host/ehci.h | 1 + > > 3 files changed, 16 insertions(+), 1 deletion(-) > > > > diff --git a/drivers/usb/host/ehci-hcd.c b/drivers/usb/host/ehci-hcd.c > > index 10b0365f3439..a539e11502ef 100644 > > --- a/drivers/usb/host/ehci-hcd.c > > +++ b/drivers/usb/host/ehci-hcd.c > > @@ -634,7 +634,15 @@ 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 = 0; > > + else > > + rc = ehci_handshake(ehci, &ehci->regs->status, STS_HALT, > > + 0, 100 * 1000); > > You must not do this. You are assuming the controller will always begin > operating within 5 ms of the time it is told to start. What happens if you are > wrong? > > There must be some way for the aspeed controller's host computer to tell > when the controller has started running. Find out what it is and use it. > > Alan Stern We can check the command RS bit to tell the controller has started running. I'll sent next patch within this change. Thanks -Neal Liu
diff --git a/drivers/usb/host/ehci-hcd.c b/drivers/usb/host/ehci-hcd.c index 10b0365f3439..a539e11502ef 100644 --- a/drivers/usb/host/ehci-hcd.c +++ b/drivers/usb/host/ehci-hcd.c @@ -634,7 +634,15 @@ 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 = 0; + 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)
STS_HALT also depends on ASS/PSS status for apseed. Skip this check on startup. Signed-off-by: neal_liu <neal_liu@aspeedtech.com> --- drivers/usb/host/ehci-hcd.c | 10 +++++++++- drivers/usb/host/ehci-platform.c | 6 ++++++ drivers/usb/host/ehci.h | 1 + 3 files changed, 16 insertions(+), 1 deletion(-)