From 610df1d2342d639ec87a8fb5290ca4799d91d59b Mon Sep 17 00:00:00 2001 From: Guenter Roeck Date: Thu, 13 Oct 2016 16:43:16 -0700 Subject: [PATCH] net: asix: Avoid looping when the device does not respond Check answers from USB stack and avoid re-sending the request multiple times if the device does not respond. This fixes the following problem, observed with a probably flaky adapter. [62108.732707] usb 1-3: new high-speed USB device number 5 using xhci_hcd [62108.914421] usb 1-3: New USB device found, idVendor=0b95, idProduct=7720 [62108.914463] usb 1-3: New USB device strings: Mfr=1, Product=2, SerialNumber=3 [62108.914476] usb 1-3: Product: AX88x72A [62108.914486] usb 1-3: Manufacturer: ASIX Elec. Corp. [62108.914495] usb 1-3: SerialNumber: 000001 [62114.109109] asix 1-3:1.0 (unnamed net_device) (uninitialized): Failed to write reg index 0x0000: -110 [62114.109139] asix 1-3:1.0 (unnamed net_device) (uninitialized): Failed to send software reset: ffffff92 [62119.109048] asix 1-3:1.0 (unnamed net_device) (uninitialized): Failed to write reg index 0x0000: -110 ... Since the USB timeout is 5 seconds, and the operation is retried 30 times, this results in [62278.180353] INFO: task mtpd:1725 blocked for more than 120 seconds. [62278.180373] Tainted: G W 3.18.0-13298-g94ace9e #1 [62278.180383] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. ... [62278.180957] kworker/2:0 D 0000000000000000 0 5744 2 0x00000000 [62278.180978] Workqueue: usb_hub_wq hub_event [62278.181029] ffff880177f833b8 0000000000000046 ffff88017fd00000 ffff88017b126d80 [62278.181048] ffff880177f83fd8 ffff880065a71b60 0000000000013340 ffff880065a71b60 [62278.181065] 0000000000000286 0000000103b1c199 0000000000001388 0000000000000002 [62278.181081] Call Trace: [62278.181092] [] ? console_conditional_schedule+0x2c/0x2c [62278.181105] [] schedule+0x69/0x6b [62278.181117] [] schedule_timeout+0xe3/0x11d [62278.181133] [] ? trace_timer_start+0x51/0x51 [62278.181146] [] do_wait_for_common+0x12f/0x16c [62278.181162] [] ? wake_up_process+0x39/0x39 [62278.181174] [] wait_for_common+0x52/0x6d [62278.181187] [] wait_for_completion_timeout+0x13/0x15 [62278.181201] [] usb_start_wait_urb+0x93/0xf1 [62278.181214] [] usb_control_msg+0xe1/0x11d [62278.181230] [] usbnet_write_cmd+0x9c/0xc6 [usbnet] [62278.181286] [] asix_write_cmd+0x4e/0x7e [asix] [62278.181300] [] asix_set_sw_mii+0x25/0x4e [asix] [62278.181314] [] asix_mdio_read+0x51/0x109 [asix] ... Signed-off-by: Guenter Roeck Signed-off-by: David S. Miller --- drivers/net/usb/asix_common.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/drivers/net/usb/asix_common.c b/drivers/net/usb/asix_common.c index f79eb12c326a..125cff57c759 100644 --- a/drivers/net/usb/asix_common.c +++ b/drivers/net/usb/asix_common.c @@ -433,13 +433,13 @@ int asix_mdio_read(struct net_device *netdev, int phy_id, int loc) mutex_lock(&dev->phy_mutex); do { ret = asix_set_sw_mii(dev, 0); - if (ret == -ENODEV) + if (ret == -ENODEV || ret == -ETIMEDOUT) break; usleep_range(1000, 1100); ret = asix_read_cmd(dev, AX_CMD_STATMNGSTS_REG, 0, 0, 1, &smsr, 0); } while (!(smsr & AX_HOST_EN) && (i++ < 30) && (ret != -ENODEV)); - if (ret == -ENODEV) { + if (ret == -ENODEV || ret == -ETIMEDOUT) { mutex_unlock(&dev->phy_mutex); return ret; } @@ -497,13 +497,13 @@ int asix_mdio_read_nopm(struct net_device *netdev, int phy_id, int loc) mutex_lock(&dev->phy_mutex); do { ret = asix_set_sw_mii(dev, 1); - if (ret == -ENODEV) + if (ret == -ENODEV || ret == -ETIMEDOUT) break; usleep_range(1000, 1100); ret = asix_read_cmd(dev, AX_CMD_STATMNGSTS_REG, 0, 0, 1, &smsr, 1); } while (!(smsr & AX_HOST_EN) && (i++ < 30) && (ret != -ENODEV)); - if (ret == -ENODEV) { + if (ret == -ENODEV || ret == -ETIMEDOUT) { mutex_unlock(&dev->phy_mutex); return ret; } -- 2.39.5