Re: [PATCH] usb: hcd: initialize hcd->flags to 0 when rm hcd
From: wlf
Date: Thu Jan 12 2017 - 21:38:04 EST
Hi Rogerï
å 2017å01æ12æ 23:38, Roger Quadros åé:
On 12/01/17 17:33, Alan Stern wrote:
On Thu, 12 Jan 2017, Roger Quadros wrote:
William,
On 12/01/17 14:03, William Wu wrote:
From: William wu <wulf@xxxxxxxxxxxxxx>
On some platforms(e.g. rk3399 board), we can call hcd_add/remove
consecutively without calling usb_put_hcd/usb_create_hcd in between,
so hcd->flags can be stale.
If the HC dies due to whatever reason then without this patch we get
the below error on next hcd_add.
[173.296154] xhci-hcd xhci-hcd.2.auto: HC died; cleaning up
[173.296209] xhci-hcd xhci-hcd.2.auto: xHCI Host Controller
[173.296762] xhci-hcd xhci-hcd.2.auto: new USB bus registered, assigned bus number 6
[173.296931] usb usb6: We don't know the algorithms for LPM for this host, disabling LPM.
[173.297179] usb usb6: New USB device found, idVendor=1d6b, idProduct=0003
[173.297203] usb usb6: New USB device strings: Mfr=3, Product=2, SerialNumber=1
[173.297222] usb usb6: Product: xHCI Host Controller
[173.297240] usb usb6: Manufacturer: Linux 4.4.21 xhci-hcd
[173.297257] usb usb6: SerialNumber: xhci-hcd.2.auto
[173.298680] hub 6-0:1.0: USB hub found
[173.298749] hub 6-0:1.0: 1 port detected
[173.299382] rockchip-dwc3 usb@fe800000: USB HOST connected
[173.395418] hub 5-0:1.0: activate --> -19
[173.603447] irq 228: nobody cared (try booting with the "irqpoll" option)
[173.603493] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.4.21 #9
[173.603513] Hardware name: Google Kevin (DT)
[173.603531] Call trace:
[173.603568] [<ffffffc0002087dc>] dump_backtrace+0x0/0x160
[173.603596] [<ffffffc00020895c>] show_stack+0x20/0x28
[173.603623] [<ffffffc0004b28a8>] dump_stack+0x90/0xb0
[173.603650] [<ffffffc00027347c>] __report_bad_irq+0x48/0xe8
[173.603674] [<ffffffc0002737cc>] note_interrupt+0x1e8/0x28c
[173.603698] [<ffffffc000270a38>] handle_irq_event_percpu+0x1d4/0x25c
[173.603722] [<ffffffc000270b0c>] handle_irq_event+0x4c/0x7c
[173.603748] [<ffffffc00027456c>] handle_fasteoi_irq+0xb4/0x124
[173.603777] [<ffffffc00026fe3c>] generic_handle_irq+0x30/0x44
[173.603804] [<ffffffc0002701a8>] __handle_domain_irq+0x90/0xbc
[173.603827] [<ffffffc0002006f4>] gic_handle_irq+0xcc/0x188
...
[173.604500] [<ffffffc000203700>] el1_irq+0x80/0xf8
[173.604530] [<ffffffc000261388>] cpu_startup_entry+0x38/0x3cc
[173.604558] [<ffffffc00090f7d8>] rest_init+0x8c/0x94
[173.604585] [<ffffffc000e009ac>] start_kernel+0x3d0/0x3fc
[173.604607] [<0000000000b16000>] 0xb16000
[173.604622] handlers:
[173.604648] [<ffffffc000642084>] usb_hcd_irq
[173.604673] Disabling IRQ #228
Signed-off-by: William wu <wulf@xxxxxxxxxxxxxx>
Signed-off-by: William wu <william.wu@xxxxxxxxxxxxxx>
---
drivers/usb/core/hcd.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/drivers/usb/core/hcd.c b/drivers/usb/core/hcd.c
index 479e223..612fab6 100644
--- a/drivers/usb/core/hcd.c
+++ b/drivers/usb/core/hcd.c
@@ -3017,6 +3017,7 @@ void usb_remove_hcd(struct usb_hcd *hcd)
}
usb_put_invalidate_rhdev(hcd);
+ hcd->flags = 0;
}
EXPORT_SYMBOL_GPL(usb_remove_hcd);
I suggest to initialize hcd->flags to 0 in usb_add_hcd() instead.
cheers,
-roger
Roger, didn't you originally propose this very same patch in
http://marc.info/?l=linux-usb&m=146556415503583&w=2
(and of course, the earlier versions before v10)? What happened to it?
Alan, You are right. That patch got lost in the ML. Looks like I didn't push it hard enough
and then forgot about it. Sorry.
William,
You don't need to do any changes. My earlier version was clearing the flag
in usb_add_hcd() and I guess Alan suggested to move it to usb_remove_hcd().
So your patch is good.
You can add my.
Acked-by: Roger Quadros <rogerq@xxxxxx>
cheers,
-roger
Thanks very much for your suggestionïI will add acked-by immediately.