Enable USB without a clock.

This causes:

[    1.107511] xhci-hcd 8b39000.xhci_v2: xHCI Host Controller
[    1.113070] xhci-hcd 8b39000.xhci_v2: new USB bus registered, assigned bus number 2
[    1.120774] usb usb2: We don't know the algorithms for LPM for this host, disabling LPM.
[    1.129082] hub 2-0:1.0: USB hub found
[    1.132904] Unhandled fault: synchronous external abort (0x1210) at 0xf09a4420
[    1.140139] pgd = bf15c398
[    1.142848] [f09a4420] *pgd=80000040007003, *pmd=6e81b003, *pte=c0000008b39713
[    1.150091] Internal error: : 1210 [#1] SMP ARM
[    1.154632] brcmstb_gisb_arb_decode_addr: die at 0x8b39420 [R ], core: cpu_0
[    1.161689] Modules linked in:
[    1.164750] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.15.0+ #133
[    1.170937] Hardware name: Broadcom STB (Flattened Device Tree)
[    1.176875] PC is at xhci_hub_control+0x234/0x1da8
[    1.181672] LR is at xhci_hub_control+0x64/0x1da8
...
[    1.657245] [<c0756990>] (xhci_hub_control) from [<c071a220>] (usb_hcd_submit_urb+0x6a4/0xa1c)
[    1.665873] [<c071a220>] (usb_hcd_submit_urb) from [<c071be98>] (usb_start_wait_urb+0x4c/0x138)
[    1.674587] [<c071be98>] (usb_start_wait_urb) from [<c071c028>] (usb_control_msg+0xa4/0xd0)
[    1.682953] [<c071c028>] (usb_control_msg) from [<c0716a74>] (hub_probe+0x2b0/0xe04)
[    1.690709] [<c0716a74>] (hub_probe) from [<c0720584>] (usb_probe_interface+0xf0/0x2a8)
[    1.698730] [<c0720584>] (usb_probe_interface) from [<c061cee8>] (driver_probe_device+0x27c/0x494)
[    1.707705] [<c061cee8>] (driver_probe_device) from [<c061b0f8>] (bus_for_each_drv+0x44/0x94)
[    1.716244] [<c061b0f8>] (bus_for_each_drv) from [<c061cb28>] (__device_attach+0xb0/0x140)
[    1.724522] [<c061cb28>] (__device_attach) from [<c061bf0c>] (bus_probe_device+0x84/0x8c)
[    1.732713] [<c061bf0c>] (bus_probe_device) from [<c061a120>] (device_add+0x3b0/0x5c0)
[    1.740644] [<c061a120>] (device_add) from [<c071e470>] (usb_set_configuration+0x47c/0x800)
[    1.749012] [<c071e470>] (usb_set_configuration) from [<c0728c6c>] (generic_probe+0x2c/0x78)
[    1.757464] [<c0728c6c>] (generic_probe) from [<c061cee8>] (driver_probe_device+0x27c/0x494)
[    1.765915] [<c061cee8>] (driver_probe_device) from [<c061b0f8>] (bus_for_each_drv+0x44/0x94)
[    1.774453] [<c061b0f8>] (bus_for_each_drv) from [<c061cb28>] (__device_attach+0xb0/0x140)
[    1.782730] [<c061cb28>] (__device_attach) from [<c061bf0c>] (bus_probe_device+0x84/0x8c)
[    1.790920] [<c061bf0c>] (bus_probe_device) from [<c061a120>] (device_add+0x3b0/0x5c0)
[    1.798850] [<c061a120>] (device_add) from [<c0713fd0>] (usb_new_device+0x1bc/0x3b4)
[    1.806606] [<c0713fd0>] (usb_new_device) from [<c071904c>] (usb_add_hcd+0x5bc/0x8e4)
[    1.814450] [<c071904c>] (usb_add_hcd) from [<c075e8e8>] (xhci_plat_probe+0x508/0x78c)
[    1.822383] [<c075e8e8>] (xhci_plat_probe) from [<c061ece4>] (platform_drv_probe+0x50/0xac)
[    1.830748] [<c061ece4>] (platform_drv_probe) from [<c061cee8>] (driver_probe_device+0x27c/0x494)
[    1.839634] [<c061cee8>] (driver_probe_device) from [<c061d200>] (__driver_attach+0x100/0x11c)
[    1.848259] [<c061d200>] (__driver_attach) from [<c061b050>] (bus_for_each_dev+0x4c/0x9c)
[    1.856450] [<c061b050>] (bus_for_each_dev) from [<c061c20c>] (bus_add_driver+0x1c0/0x264)
[    1.864727] [<c061c20c>] (bus_add_driver) from [<c061dda4>] (driver_register+0x78/0xf4)
[    1.872747] [<c061dda4>] (driver_register) from [<c0201b48>] (do_one_initcall+0x44/0x168)
[    1.880945] [<c0201b48>] (do_one_initcall) from [<c0e00dd4>] (kernel_init_freeable+0x144/0x1d0)
[    1.889663] [<c0e00dd4>] (kernel_init_freeable) from [<c097f858>] (kernel_init+0x8/0x110)
[    1.897860] [<c097f858>] (kernel_init) from [<c0208798>] (ret_from_fork+0x14/0x3c)

Signed-off-by: Eric Anholt <[email protected]>

Author: anholt

drivers/usb/host/xhci-plat.c

@@ -235,8 +235,7 @@ static int xhci_plat_probe(struct platform_device *pdev)
 		if (ret)
 			goto put_hcd;
 	} else if (PTR_ERR(clk) == -EPROBE_DEFER) {
-		ret = -EPROBE_DEFER;
-		goto put_hcd;
+		clk = NULL;
 	}
 
 	xhci = hcd_to_xhci(hcd);