Messages in this thread | | | Subject | Re: [PATCH v1 1/1] usb: xhci: do not create and register shared_hcd when USB3.0 is disabled | From | Mathias Nyman <> | Date | Thu, 18 Jan 2018 17:02:30 +0200 |
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On 18.01.2018 09:27, Tung Vuong Nguyen wrote: > On Tue, Jan 16, 2018 at 9:50 PM, Mathias Nyman > <mathias.nyman@linux.intel.com> wrote: >> >> Hi, Sorry about the delay >> >> >> On 04.01.2018 07:17, Thang Q. Nguyen wrote: >>> >>> Hi, >>> >>> On Sat, Dec 16, 2017 at 10:45 AM, Thang Q. Nguyen <tqnguyen@apm.com> wrote: >>>> >>>> From: Tung Nguyen <tunguyen@apm.com> >>>> >>>> Currently, hcd->shared_hcd always creates and registers to the usb-core. >>>> If, for some reasons, USB3 downstream port is disabled, no roothub port for >>>> USB3.0 is found. This causes kernel to display an error: >>>> hub 2-0:1.0: config failed, hub doesn't have any ports! (err -19) >>>> This patch checks, creates and registers shared_hcd if USB3.0 downstream >>>> port is available. >>>> >>>> Signed-off-by: Tung Nguyen <tunguyen@apm.com> >>>> Signed-off-by: Thang Q. Nguyen <tqnguyen@apm.com> >>>> --- >>>> drivers/usb/host/xhci-mem.c | 2 +- >>>> drivers/usb/host/xhci-plat.c | 26 +++++++++++---------- >>>> drivers/usb/host/xhci.c | 54 ++++++++++++++++++++++++++++++++------------ >>>> 3 files changed, 54 insertions(+), 28 deletions(-) >>>> >>>> diff --git a/drivers/usb/host/xhci-mem.c b/drivers/usb/host/xhci-mem.c >>>> index 554a8a5..157d1e7 100644 >>>> --- a/drivers/usb/host/xhci-mem.c >>>> +++ b/drivers/usb/host/xhci-mem.c >>>> @@ -1067,7 +1067,7 @@ static u32 xhci_find_real_port_number(struct xhci_hcd *xhci, >>>> struct usb_device *top_dev; >>>> struct usb_hcd *hcd; >>>> >>>> - if (udev->speed >= USB_SPEED_SUPER) >>>> + if (udev->speed >= USB_SPEED_SUPER && xhci->shared_hcd) >>>> hcd = xhci->shared_hcd; >>>> else >>>> hcd = xhci->main_hcd; >>>> diff --git a/drivers/usb/host/xhci-plat.c b/drivers/usb/host/xhci-plat.c >>>> index 6f03830..e812e3d 100644 >>>> --- a/drivers/usb/host/xhci-plat.c >>>> +++ b/drivers/usb/host/xhci-plat.c >>>> @@ -253,12 +253,6 @@ static int xhci_plat_probe(struct platform_device *pdev) >>>> >>>> xhci->clk = clk; >>>> xhci->main_hcd = hcd; >>>> - xhci->shared_hcd = __usb_create_hcd(driver, sysdev, &pdev->dev, >>>> - dev_name(&pdev->dev), hcd); >>>> - if (!xhci->shared_hcd) { >>>> - ret = -ENOMEM; >>>> - goto disable_clk; >>>> - } >>>> >>>> if (device_property_read_bool(sysdev, "usb2-lpm-disable")) >>>> xhci->quirks |= XHCI_HW_LPM_DISABLE; >>>> @@ -290,12 +284,20 @@ static int xhci_plat_probe(struct platform_device *pdev) >>>> if (ret) >>>> goto disable_usb_phy; >>>> >>>> - if (HCC_MAX_PSA(xhci->hcc_params) >= 4) >>>> - xhci->shared_hcd->can_do_streams = 1; >>>> - >>>> - ret = usb_add_hcd(xhci->shared_hcd, irq, IRQF_SHARED); >>>> - if (ret) >>>> - goto dealloc_usb2_hcd; >>>> + if (xhci->num_usb3_ports > 0) { >>>> + xhci->shared_hcd = __usb_create_hcd(driver, sysdev, &pdev->dev, >>>> + dev_name(&pdev->dev), hcd); >>>> + if (!xhci->shared_hcd) { >>>> + ret = -ENOMEM; >>>> + goto disable_clk; >>>> + } >>>> + if (HCC_MAX_PSA(xhci->hcc_params) >= 4) >>>> + xhci->shared_hcd->can_do_streams = 1; >>>> + >>>> + ret = usb_add_hcd(xhci->shared_hcd, irq, IRQF_SHARED); >>>> + if (ret) >>>> + goto dealloc_usb2_hcd; >>>> + } >>>> >>>> device_enable_async_suspend(&pdev->dev); >>>> pm_runtime_put_noidle(&pdev->dev); >>>> diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c >>>> index 05104bd..4824bf6 100644 >>>> --- a/drivers/usb/host/xhci.c >>>> +++ b/drivers/usb/host/xhci.c >>>> @@ -417,12 +417,14 @@ static void compliance_mode_recovery(struct timer_list *t) >>>> i + 1); >>>> xhci_dbg_trace(xhci, trace_xhci_dbg_quirks, >>>> "Attempting compliance mode recovery"); >>>> - hcd = xhci->shared_hcd; >>>> + if (xhci->shared_hcd) { >>>> + hcd = xhci->shared_hcd; >>>> >>>> - if (hcd->state == HC_STATE_SUSPENDED) >>>> - usb_hcd_resume_root_hub(hcd); >>>> + if (hcd->state == HC_STATE_SUSPENDED) >>>> + usb_hcd_resume_root_hub(hcd); >>>> >>>> - usb_hcd_poll_rh_status(hcd); >>>> + usb_hcd_poll_rh_status(hcd); >>>> + } >>>> } >>>> } >>>> >>>> @@ -611,6 +613,18 @@ int xhci_run(struct usb_hcd *hcd) >>>> if (ret) >>>> xhci_free_command(xhci, command); >>>> } >>>> + /* >>>> + * Execute xhci_start() in case xhci->shared_hcd is not registered. >>>> + * If the xhci->shared_hcd doesn't exist, no one triggers to start >>>> + * the xhci which should be done before exitting run function >>>> + */ >>>> + if (!xhci->shared_hcd) { >>>> + if (xhci_start(xhci)) { >> >> >> This probably won't work as primary hcd was added before shared_hcd was created. >> usb_add_hcd(hcd) calls xhci_run() before xhci->shared_hcd exists, so this will >> cause the xHC to start before the shared_hcd is created or setup. >> >> -Mathias > > Hi Mathias > I ran the test and saw the patch works fine in 2 cases: > xhci->num_usb3_ports = 0 and xhci->num_usb3_ports > 0. > For the case that we don't have the usb 3.0, the standalone > primary_hcd should work without the share_hcd. This case the root hubs > run at speed 480M. > If we have xhci->num_usb3_ports > 0 then we have 2 times to trigger to > start xHC in xhci_run. Once by the primary_hcd and once by share_hcd. > We will have 5000M root hubs and following by 480M root hubs when > triggering by the share_hcd and as properly. > > So the xHC should works when we only have primary_hcd or we have both > primary hcd and share_hcd > > Here is the brief of the scenario for this patch: > + create the primary hcd in xhci-plat > + execute usb_add_hcd(hcd), execute xhci_run and start the xHC (for primary hcd) > + if the xhci->num_usb3_ports > 0 then: > + create the share_hcd structure > + execute usb_add_hcd(share_hcd), execute xhci_run and start > the xHC again (for share_hcd) > + The root hub run at 5000M > else if xhci->num_usb3_ports == 0 then: > + don't create the share_hcd structure > + don't usb_add_hcd(share_hcd) > + the xHC can run with root hub 480M > > Please share your ideas for something should be changed. >
original xhci_plat probe: ------------------------- usb_create_hcd(hcd) // USB2 usb_create_hcd(shared) // USB3 xhci->shared_hcd exists now, and hcd->primary is set for the USB3 hcd usb_add_hcd(hcd) // USB2 hcd->driver->start(hcd) // = .xhci_run() if (!usb_hcd_is_primary_hcd(hcd)) // FALSE, this is the primary USB2 else do other setup stuff usb_add_hcd(shared) // USB3 hcd->driver->start(shared) // = .xhci_run() if (!usb_hcd_is_primary_hcd(hcd)) // TRUE, this is the secondary USB3 xhci_run_finished() xhci_start() actually write bit to xHC that starts conrtoller.
so xHC HW is not really processing anyting before everything is ready
xhci_plat probe after this patch: --------------------------------- usb_create_hcd(hcd) // USB2 usb_add_hcd(hcd) // USB2 hcd->driver->start(hcd) // = .xhci_run() if (!xhci->shared_hcd) // TRUE, shared HCD is not yet created if (xhci_start(xhci)) actually write bit to xHC that starts controller. // <------------ THIS IS THE PROBLEM usb_create_hcd(shared) // USB3 xhci->shared_hcd exists now usb_add_hcd(shared) // USB3 hcd->driver->start(shared) // = .xhci_run() ...
So there is a time when xHC HW is processing but the USB3 side in driver is not properly set up yet.
-Mathias
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