On Sat, May 03, 2014 at 11:52:25AM +0800, xiao jin wrote:
> We use usb ehci to connect with modem and run stress test on ehci
> remote wake. Sometimes usb disconnect. We add more debug ftrace
> (Kernel version: 3.10) and list the key log to show how problem
> happened.
>
> <idle>-0 [000] d.h2 26879.385095: ehci_irq: irq status 1008c PPCE FLR PCD
> <idle>-0 [000] d.h2 26879.385099: ehci_irq: rh_state[2] hcd->state[132] pstatus[0][238014c5] suspended_ports[1] reset_done[0]
> <...>-12873 [000] d..1 26879.393536: ehci_hub_control: GetStatus port:1 status 238014c5 17 ERR POWER sig=k SUSPEND RESUME PE CONNECT
> <...>-12873 [000] d..1 26879.393549: ehci_hub_control: typeReq [2301] wIndex[1] wValue[2]
> <...>-12873 [000] d..1 26879.393553: ehci_hub_control: [ehci_hub_control]line[891] port[0] hostpc_reg [44000202]->[44000202]
> <idle>-0 [001] ..s. 26879.403122: ehci_hub_status_data: wgq[ehci_hub_status_data] ignore_oc[0] resuming_ports[1]
> <...>-12873 [000] d..1 26879.413379: ehci_hub_control: [ehci_hub_control]line[907] port[0] write portsc_reg[238014c5] reset_done[2105769]
> <...>-12873 [000] d..1 26879.453173: ehci_hub_control: GetStatus port:1 status 23801885 17 ERR POWER sig=j SUSPEND PE CONNECT
> <...>-12873 [000] .... 26879.473158: check_port_resume_type: port 1 status 0000.0507 after resume, -19
> <...>-12873 [000] .... 26879.473160: usb_port_resume: status = -19 after check_port_resume_type
> <...>-12873 [000] .... 26879.473161: usb_port_resume: can't resume, status -19
> <...>-12873 [000] .... 26879.473162: hub_port_logical_disconnect: logical disconnect on port 1
>
> There is a in-band remote wakeup and controller run in k-state. Then kernel
> driver(ClearPortFeature/USB_PORT_FEAT_SUSPEND) write RESUME|LS(k-state) bit
> into controller. It makes controller status weird. It's defined in EHCI
Are you sure you are at this path? If there is a remote wakeup, the
sending resume signal from host controller will be skipped
(USB_PORT_FEAT_SUSPEND), see usb_port_resume at drivers/usb/core/hub.c.
> controller spec(Revision 1.0), "If it has enabled remote wake-up, a K-state
> on the bus will turn the transceiver clock and generate an interrupt. The
> software will then have to wait 20 ms for the resume to complete and the
> port to go back to an active state." In this case Kernel should wait for
> the wakeup finished, then judge what should do next step.
Do you use a chipidea core? Try to do not clear run/stop to see if this
problem is fixed or not.
>
> We have some thought and give a patch. This patch is to wait for controller
> RESUME finished when hub try to clear port SUSPEND feature.
>
> Signed-off-by: xiao jin <jin.xiao@xxxxxxxxx>
> Reviewed-by: David Cohen <david.a.cohen@xxxxxxxxxxxxxxx>
> ---
> drivers/usb/host/ehci-hub.c | 7 +++++++
> include/linux/usb/ehci_def.h | 5 +++++
> 2 files changed, 12 insertions(+)
>
> diff --git a/drivers/usb/host/ehci-hub.c b/drivers/usb/host/ehci-hub.c
> index 7ae0c4d..09a8b6b 100644
> --- a/drivers/usb/host/ehci-hub.c
> +++ b/drivers/usb/host/ehci-hub.c
> @@ -935,6 +935,13 @@ static int ehci_hub_control (
> break;
> }
> #endif
> + if ((temp & PORT_RESUME)
> + && ((temp & PORT_LS_MASK) == PORT_K_STATE)) {
> + ehci_handshake(ehci, status_reg,
> + PORT_RESUME, 0, 20000 /* 20msec */);
> + temp = ehci_readl(ehci, status_reg);
> + temp &= ~PORT_RWC_BITS;
> + }
> if (!(temp & PORT_SUSPEND))
> break;
> if ((temp & PORT_PE) == 0)
> diff --git a/include/linux/usb/ehci_def.h b/include/linux/usb/ehci_def.h
> index daec99a..0f0f919 100644
> --- a/include/linux/usb/ehci_def.h
> +++ b/include/linux/usb/ehci_def.h
> @@ -149,6 +149,11 @@ struct ehci_regs {
> #define PORT_POWER (1<<12) /* true: has power (see PPC) */
> #define PORT_USB11(x) (((x)&(3<<10)) == (1<<10)) /* USB 1.1 device */
> /* 11:10 for detecting lowspeed devices (reset vs release ownership) */
> +#define PORT_LS_MASK (0x3<<10) /* line status */
> +#define PORT_SE0_STATE (0<<10)
> +#define PORT_K_STATE (1<<10)
> +#define PORT_J_STATE (2<<10)
> +#define PORT_UNDEFINED_STATE (3<<10)
> /* 9 reserved */
> #define PORT_LPM (1<<9) /* LPM transaction */
> #define PORT_RESET (1<<8) /* reset port */
> --
> 1.7.9.5
>
> --
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--
Best Regards,
Peter Chen
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