Re: [PATCH v1 1/1] usb: xhci: do not create and register shared_hcd when USB3.0 is disabled
From: Mathias Nyman
Date: Thu Jan 18 2018 - 09:59:53 EST
On 18.01.2018 09:27, Tung Vuong Nguyen wrote:
On Tue, Jan 16, 2018 at 9:50 PM, Mathias Nyman
<mathias.nyman@xxxxxxxxxxxxxxx> 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@xxxxxxx> wrote:
From: Tung Nguyen <tunguyen@xxxxxxx>
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@xxxxxxx>
Signed-off-by: Thang Q. Nguyen <tqnguyen@xxxxxxx>
---
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