by Mathy Vanhoef

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Subject: Re: [PATCH] brcmfmac: unlink URB when request timed out

Using usb_kill_urb() instead of usb_unlink_urb() seems to work without any problems.

On 11/11/2014 06:05 AM, Arend van Spriel wrote:
> On 10-11-14 17:08, Mathy Vanhoef wrote:
>> On 11/10/2014 06:18 AM, Arend van Spriel wrote:
>>> On 09-11-14 19:10, Mathy Vanhoef wrote:
>>>> From: Mathy Vanhoef <[email protected]>
>>>>
>>>> Unlink the submitted URB in brcmf_usb_dl_cmd if the request timed out. This
>>>> assures the URB is never submitted twice, preventing a driver crash.
>>>
>>> Hi Mathy,
>>>
>>> What driver crash are you referring to? The log only shows the WARNING
>>> ending in a USB disconnect but no actual crash. Does your patch get the
>>> driver running properly or does it only avoid the warning.
>>
>> Hi Arend,
>>
>> It shows a warning, after which the device doesn't work (but the computer is
>> still usable). But I've noticed that when *unplugging* the USB cable the OS may
>> freeze. This doesn't always happen though, sometimes unplugging works OK. The
>> patch both avoids the warning, and gets the device/driver running properly
>> (unplugging also works OK).
>>
>>>
>>> With that said, it seems there is some need for improvement, but I also
>>> notice you are running this on a virtual machine so could that affect
>>> the timeout to kick in before completion. Could you try to increase the
>>> timeout. Still when a timeout occurs this needs to be handled properly.
>>> Could you also try the following patch?
>>
>> I did a few additional tests:
>>
>> 1. When increasing IOCTL_RESP_TIMEOUT to 20000 (ten times the normal value) the
>> timeout and warning still occur. Device/driver doesn't work.
>> 2. When increasing BRCMF_USB_RESET_GETVER_SPINWAIT to 1000 (ten timers the
>> normal value) everything works. Device/driver works.
>
> This means the ctl_urb completes on your system within 3sec, but not
> within 2.1sec. After discussing this with my colleague, we think you
> should use usb_kill_urb() instead of usb_unlink_urb() as it assures the
> completion handler is called. Could you retest that and let us know.
>
> Regards,
> Arend
>
>> 3. Quick test using backports-3.18-rc1-1 (aka unpatched driver) on a non-
>> virtualized Linux install: In that case everything worked fine. So the bug
>> may only be triggered in a virtualized environment / VMWare.
>> 4. When applying your patch, the driver stops early during initialization of
>> the device. I included a WARN_ONCE before returning EINVAL and got the
>> output below.
>>
>> Kind regards,
>> Mathy
>> ---
>> [ 220.955647] usb 1-1: new high-speed USB device number 3 using ehci-pci
>> [ 221.487797] usb 1-1: New USB device found, idVendor=043e, idProduct=3004
>> [ 221.487802] usb 1-1: New USB device strings: Mfr=1, Product=2, SerialNumber=3
>> [ 221.487804] usb 1-1: Product: Remote Download Wireless Adapter
>> [ 221.487806] usb 1-1: Manufacturer: Broadcom
>> [ 221.487808] usb 1-1: SerialNumber: 000000000001
>> [ 221.490472] brcmfmac: brcmf_usb_probe Enter 0x043e:0x3004
>> [ 221.490476] brcmfmac: brcmf_usb_probe Broadcom high speed USB WLAN interface detected
>> [ 221.490477] brcmfmac: brcmf_usb_probe_cb Enter
>> [ 221.490480] brcmfmac: brcmf_usb_attach Enter
>> [ 221.490494] brcmfmac: brcmf_usb_dlneeded Enter
>> [ 221.490495] ------------[ cut here ]------------
>> [ 221.490503] WARNING: CPU: 0 PID: 100 at drivers/net/wireless/brcm80211/brcmfmac/usb.c:716 brcmf_usb_dl_cmd+0x75/0x1a0 [brcmfmac]()
>> [ 221.490505] EINVAL devinfo=c0044000 ctl_rub=ef898380 completed=0
>> [ 221.490506] Modules linked in: brcmfmac brcmutil vmw_pvscsi pcnet32 mptspi mptscsih mptbase
>> [ 221.490514] CPU: 0 PID: 100 Comm: kworker/0:1 Not tainted 3.18.0-rc3-wl+ #2
>> [ 221.490515] Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 07/31/2013
>> [ 221.490528] Workqueue: usb_hub_wq hub_event
>> [ 221.490530] 00000000 00000000 eecffb58 c1711f4a eecffb98 eecffb88 c103edaf f11cbc58
>> [ 221.490534] eecffbb4 00000064 f11cbc84 000002cc f11c1595 f11c1595 c0044000 ffffffea
>> [ 221.490537] ef726000 eecffba0 c103ee4e 00000009 eecffb98 f11cbc58 eecffbb4 eecffbd0
>> [ 221.490541] Call Trace:
>> [ 221.490550] [<c1711f4a>] dump_stack+0x41/0x52
>> [ 221.490558] [<c103edaf>] warn_slowpath_common+0x7f/0xa0
>> [ 221.490563] [<f11c1595>] ? brcmf_usb_dl_cmd+0x75/0x1a0 [brcmfmac]
>> [ 221.490567] [<f11c1595>] ? brcmf_usb_dl_cmd+0x75/0x1a0 [brcmfmac]
>> [ 221.490570] [<c103ee4e>] warn_slowpath_fmt+0x2e/0x30
>> [ 221.490575] [<f11c1595>] brcmf_usb_dl_cmd+0x75/0x1a0 [brcmfmac]
>> [ 221.490580] [<f11c2cd8>] brcmf_usb_probe+0x3c8/0x640 [brcmfmac]
>> [ 221.490583] [<c1717d53>] ? mutex_lock+0x13/0x32
>> [ 221.490586] [<c1493ae3>] usb_probe_interface+0xa3/0x180
>> [ 221.490590] [<c13f5690>] ? __driver_attach+0x90/0x90
>> [ 221.490592] [<c13f546e>] driver_probe_device+0x5e/0x1f0
>> [ 221.490595] [<c13f5690>] ? __driver_attach+0x90/0x90
>> [ 221.490597] [<c13f56c9>] __device_attach+0x39/0x50
>> [ 221.490600] [<c13f3d84>] bus_for_each_drv+0x34/0x70
>> [ 221.490602] [<c13f53db>] device_attach+0x7b/0x90
>> [ 221.490604] [<c13f5690>] ? __driver_attach+0x90/0x90
>> [ 221.490607] [<c13f4b8f>] bus_probe_device+0x6f/0x90
>> [ 221.490609] [<c13f3256>] device_add+0x426/0x520
>> [ 221.490611] [<c1491503>] ? usb_control_msg+0xb3/0xd0
>> [ 221.490614] [<c1717d53>] ? mutex_lock+0x13/0x32
>> [ 221.490627] [<c14922f8>] usb_set_configuration+0x3f8/0x700
>> [ 221.490630] [<c13f5690>] ? __driver_attach+0x90/0x90
>> [ 221.490633] [<c149ac7b>] generic_probe+0x2b/0x90
>> [ 221.490637] [<c1188bc0>] ? sysfs_create_link+0x20/0x40
>> [ 221.490639] [<c1492bec>] usb_probe_device+0xc/0x10
>> [ 221.490641] [<c13f546e>] driver_probe_device+0x5e/0x1f0
>> [ 221.490644] [<c13f5690>] ? __driver_attach+0x90/0x90
>> [ 221.490646] [<c13f56c9>] __device_attach+0x39/0x50
>> [ 221.490649] [<c13f3d84>] bus_for_each_drv+0x34/0x70
>> [ 221.490651] [<c13f53db>] device_attach+0x7b/0x90
>> [ 221.490653] [<c13f5690>] ? __driver_attach+0x90/0x90
>> [ 221.490656] [<c13f4b8f>] bus_probe_device+0x6f/0x90
>> [ 221.490658] [<c13f3256>] device_add+0x426/0x520
>> [ 221.490661] [<c148aa2e>] ? usb_new_device+0x16e/0x3a0
>> [ 221.490663] [<c148aad7>] usb_new_device+0x217/0x3a0
>> [ 221.490666] [<c148bff7>] hub_event+0xa17/0xda0
>> [ 221.490668] [<c1716918>] ? __schedule+0x2f8/0x710
>> [ 221.490672] [<c105127c>] ? pwq_dec_nr_in_flight+0x3c/0x90
>> [ 221.490674] [<c10513ee>] process_one_work+0x11e/0x360
>> [ 221.490677] [<c1051750>] worker_thread+0xf0/0x3c0
>> [ 221.490680] [<c106e14a>] ? __wake_up_locked+0x1a/0x20
>> [ 221.490682] [<c1051660>] ? process_scheduled_works+0x30/0x30
>> [ 221.490685] [<c1055b56>] kthread+0x96/0xb0
>> [ 221.490687] [<c1050000>] ? put_unbound_pool+0x110/0x170
>> [ 221.490691] [<c1719c81>] ret_from_kernel_thread+0x21/0x30
>> [ 221.490693] [<c1055ac0>] ? kthread_worker_fn+0x110/0x110
>> [ 221.490695] ---[ end trace 9befd914693f3083 ]---
>> [ 221.490697] brcmfmac: brcmf_usb_dlneeded chip 57005 rev 0xf11cfcec
>> [ 221.490699] brcmfmac: brcmf_fw_get_firmwares enter: dev=1-1
>>
>> diff --git a/drivers/net/wireless/brcm80211/brcmfmac/usb.c b/drivers/net/wireless/brcm80211/brcmfmac/usb.c
>> index 5265aa7..15b1aa7 100644
>> --- a/drivers/net/wireless/brcm80211/brcmfmac/usb.c
>> +++ b/drivers/net/wireless/brcm80211/brcmfmac/usb.c
>> @@ -709,8 +709,13 @@ static int brcmf_usb_dl_cmd(struct brcmf_usbdev_info *devinfo, u8 cmd,
>> char *tmpbuf;
>> u16 size;
>>
>> - if ((!devinfo) || (devinfo->ctl_urb == NULL))
>> + if (!devinfo || !devinfo->ctl_urb || !devinfo->ctl_completed) {
>> + WARN_ONCE(1, "EINVAL devinfo=%p ctl_rub=%p completed=%d\n",
>> + devinfo,
>> + devinfo ? devinfo->ctl_urb : NULL,
>> + devinfo ? devinfo->ctl_completed : -1);
>> return -EINVAL;
>> + }
>>
>> tmpbuf = kmalloc(buflen, GFP_ATOMIC);
>> if (!tmpbuf)
>>
>>
>>>
>>> Regards,
>>> Arend
>>> ---
>>> drivers/net/wireless/brcm80211/brcmfmac/usb.c | 2 +-
>>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>>
>>> diff --git a/drivers/net/wireless/brcm80211/brcmfmac/usb.c
>>> b/drivers/net/wireles
>>> index dc13591..786c40b 100644
>>> --- a/drivers/net/wireless/brcm80211/brcmfmac/usb.c
>>> +++ b/drivers/net/wireless/brcm80211/brcmfmac/usb.c
>>> @@ -640,7 +640,7 @@ static int brcmf_usb_dl_cmd(struct brcmf_usbdev_info
>>> *devinf
>>> char *tmpbuf;
>>> u16 size;
>>>
>>> - if ((!devinfo) || (devinfo->ctl_urb == NULL))
>>> + if (!devinfo || !devinfo->ctl_urb || !devinfo->ctl_completed)
>>> return -EINVAL;
>>>
>>> tmpbuf = kmalloc(buflen, GFP_ATOMIC);
>>>
>>>> Signed-off-by: Mathy Vanhoef <[email protected]>
>>>> ---
>>>> Currently brcmfmac may crash when a USB device is attached (tested with a LG
>>>> TWFM-B003D). In particular it fails on the second call to brcmf_usb_dl_cmd in
>>>> the while loop of brcmf_usb_resetcfg. The problem is that an URB is being
>>>> submitted twice:
>>>>
>>>> [ 169.861800] brcmfmac: brcmf_usb_dl_writeimage Enter, fw f14db000, len 348160
>>>> [ 171.787791] brcmfmac: brcmf_usb_dl_writeimage Exit, err=0
>>>> [ 171.787797] brcmfmac: brcmf_usb_dlstart Exit, err=0
>>>> [ 171.787799] brcmfmac: brcmf_usb_dlrun Enter
>>>> [ 171.791794] brcmfmac: brcmf_usb_resetcfg Enter
>>>> [ 173.988072] ------------[ cut here ]------------
>>>> [ 173.988083] WARNING: CPU: 0 PID: 369 at drivers/usb/core/urb.c:339 usb_submit_urb+0x4e6/0x500()
>>>> [ 173.988085] URB eaf45f00 submitted while active
>>>> [ 173.988086] Modules linked in: brcmfmac brcmutil vmw_pvscsi pcnet32 mptspi mptscsih mptbase
>>>> [ 173.988100] CPU: 0 PID: 369 Comm: kworker/0:2 Not tainted 3.18.0-rc3-wl #1
>>>> [ 173.988102] Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 07/31/2013
>>>> [ 173.988106] Workqueue: events request_firmware_work_func
>>>> [ 173.988108] 00000000 00000000 ee747db8 c1711f4a ee747df8 ee747de8 c103edaf c18d1e10
>>>> [ 173.988112] ee747e14 00000171 c18a8b29 00000153 c1490556 c1490556 eaf45f00 eafdc660
>>>> [ 173.988115] f14b8fa0 ee747e00 c103ee4e 00000009 ee747df8 c18d1e10 ee747e14 ee747e50
>>>> [ 173.988119] Call Trace:
>>>> [ 173.988129] [<c1711f4a>] dump_stack+0x41/0x52
>>>> [ 173.988136] [<c103edaf>] warn_slowpath_common+0x7f/0xa0
>>>> [ 173.988139] [<c1490556>] ? usb_submit_urb+0x4e6/0x500
>>>> [ 173.988141] [<c1490556>] ? usb_submit_urb+0x4e6/0x500
>>>> [ 173.988147] [<f14b8fa0>] ? brcmf_usb_ioctl_resp_wake+0x40/0x40 [brcmfmac]
>>>> [ 173.988150] [<c103ee4e>] warn_slowpath_fmt+0x2e/0x30
>>>> [ 173.988152] [<c1490556>] usb_submit_urb+0x4e6/0x500
>>>> [ 173.988156] [<c1123de1>] ? __kmalloc+0x21/0x140
>>>> [ 173.988161] [<f14b91c3>] ? brcmf_usb_dl_cmd+0x33/0x120 [brcmfmac]
>>>> [ 173.988166] [<f14b9243>] brcmf_usb_dl_cmd+0xb3/0x120 [brcmfmac]
>>>> [ 173.988170] [<f14ba6c4>] brcmf_usb_probe_phase2+0x4e4/0x640 [brcmfmac]
>>>> [ 173.988176] [<f14b4900>] brcmf_fw_request_code_done+0xd0/0xf0 [brcmfmac]
>>>> [ 173.988178] [<c1400876>] request_firmware_work_func+0x26/0x50
>>>> [ 173.988182] [<c10513ee>] process_one_work+0x11e/0x360
>>>> [ 173.988184] [<c1051750>] worker_thread+0xf0/0x3c0
>>>> [ 173.988205] [<c106e14a>] ? __wake_up_locked+0x1a/0x20
>>>> [ 173.988208] [<c1051660>] ? process_scheduled_works+0x30/0x30
>>>> [ 173.988211] [<c1055b56>] kthread+0x96/0xb0
>>>> [ 173.988214] [<c1719c81>] ret_from_kernel_thread+0x21/0x30
>>>> [ 173.988217] [<c1055ac0>] ? kthread_worker_fn+0x110/0x110
>>>> [ 173.988219] ---[ end trace 0c88bf46801de083 ]---
>>>> [ 173.988221] brcmf_usb_dl_cmd: usb_submit_urb failed -16
>>>> [ 173.988396] brcmfmac: brcmf_usb_probe_phase2 failed: dev=1-1, err=-19
>>>> [ 173.989503] brcmfmac: brcmf_usb_disconnect Enter
>>>>
>>>> This patch fixes the brcmf_usb_dl_cmd function to prevent an URB from being
>>>> submitted twice. Tested using a LG TWFM-B003D, which now works properly.
>>>>
>>>>
>>>> drivers/net/wireless/brcm80211/brcmfmac/usb.c | 6 ++++--
>>>> 1 file changed, 4 insertions(+), 2 deletions(-)
>>>>
>>>> diff --git a/drivers/net/wireless/brcm80211/brcmfmac/usb.c b/drivers/net/wireless/brcm80211/brcmfmac/usb.c
>>>> index 5265aa7..1bc7858 100644
>>>> --- a/drivers/net/wireless/brcm80211/brcmfmac/usb.c
>>>> +++ b/drivers/net/wireless/brcm80211/brcmfmac/usb.c
>>>> @@ -738,10 +738,12 @@ static int brcmf_usb_dl_cmd(struct brcmf_usbdev_info *devinfo, u8 cmd,
>>>> goto finalize;
>>>> }
>>>>
>>>> - if (!brcmf_usb_ioctl_resp_wait(devinfo))
>>>> + if (!brcmf_usb_ioctl_resp_wait(devinfo)) {
>>>> + usb_unlink_urb(devinfo->ctl_urb);
>>>> ret = -ETIMEDOUT;
>>>> - else
>>>> + } else {
>>>> memcpy(buffer, tmpbuf, buflen);
>>>> + }
>>>>
>>>> finalize:
>>>> kfree(tmpbuf);
>>>>
>>>
>