RE: [PATCH] mei: Abort writes if incomplete after 1s
From: Winkler, Tomas
Date: Tue Jul 23 2019 - 07:25:22 EST
>
> During i915 unload, it appears that it may get stuck waiting on a workqueue
> being hogged by mei:
Thanks for the bug report, but this is not a proper fix, we will try to work it out.
Thanks
Tomas
>
> <7> [212.666912] i915 0000:00:02.0: [drm:drm_client_release] drm_fb_helper
> <3> [308.544943] INFO: task i915_module_loa:2612 blocked for more than 61
> seconds.
> <3> [308.545047] Tainted: G U W 5.3.0-rc1-CI-CI_DRM_6537+ #1
> <3> [308.545085] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables
> this message.
> <6> [308.545128] i915_module_loa D13256 2612 960 0x00004004
> <4> [308.545137] Call Trace:
> <4> [308.545150] ? __schedule+0x326/0x890 <4> [308.545159] ?
> wait_for_common+0x116/0x1f0 <4> [308.545164] schedule+0x2b/0xb0 <4>
> [308.545169] schedule_timeout+0x219/0x3c0 <4> [308.545176] ?
> wait_for_common+0x132/0x1f0 <4> [308.545183] ?
> _raw_spin_unlock_irq+0x24/0x30 <4> [308.545189] ?
> wait_for_common+0x116/0x1f0 <4> [308.545193]
> wait_for_common+0x13a/0x1f0 <4> [308.545200] ? wake_up_q+0x80/0x80
> <4> [308.545209] flush_workqueue+0x19d/0x540 <4> [308.545334] ?
> intel_modeset_driver_remove+0xb3/0x140 [i915] <4> [308.545407]
> intel_modeset_driver_remove+0xb3/0x140 [i915] <4> [308.545464]
> i915_driver_remove+0xae/0x110 [i915] <4> [308.545522]
> i915_pci_remove+0x19/0x30 [i915] <4> [308.545529]
> pci_device_remove+0x36/0xb0
>
> <6> [308.565422] Showing busy workqueues and worker pools:
> <6> [308.565425] workqueue events: flags=0x0
> <6> [308.565572] pwq 2: cpus=1 node=0 flags=0x0 nice=0 active=2/256
> <6> [308.565635] in-flight: 441:mei_cl_bus_rescan_work [mei]
> <6> [308.565641] pending: dbs_work_handler
> <6> [308.565686] pool 2: cpus=1 node=0 flags=0x0 nice=0 hung=0s workers=5
> idle: 2248 21 17 169
>
> <6> [308.553788] Workqueue: events mei_cl_bus_rescan_work [mei] <4>
> [308.553792] Call Trace:
> <4> [308.553799] ? __schedule+0x326/0x890 <4> [308.553808]
> schedule+0x2b/0xb0 <4> [308.553815] mei_cl_write+0x430/0x5a0 [mei] <4>
> [308.553820] ? __kmalloc+0x2b6/0x330 <4> [308.553824] ?
> wait_woken+0xa0/0xa0 <4> [308.553835] __mei_cl_send+0x1f4/0x240 [mei]
> <4> [308.553848] mei_mkhi_fix+0x91/0x280 [mei] <4> [308.553859]
> mei_cl_bus_dev_fixup+0xba/0x100 [mei] <4> [308.553868] ?
> device_add+0x156/0x670 <4> [308.553889] ?
> mei_cl_bus_rescan_work+0x1bc/0x350 [mei] <4> [308.553896]
> mei_cl_bus_rescan_work+0x1bc/0x350 [mei] <4> [308.553905]
> process_one_work+0x245/0x5f0 <4> [308.553915] worker_thread+0x37/0x380
> <4> [308.553921] ? process_one_work+0x5f0/0x5f0 <4> [308.553924]
> kthread+0x119/0x130 <4> [308.553928] ? kthread_park+0xa0/0xa0 <4>
> [308.553934] ret_from_fork+0x3a/0x50
>
> Signed-off-by: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx>
> Cc: Alexander Usyskin <alexander.usyskin@xxxxxxxxx>
> Cc: Tomas Winkler <tomas.winkler@xxxxxxxxx>
> ---
> drivers/misc/mei/bus.c | 9 +++++++--
> drivers/misc/mei/client.c | 5 +++--
> drivers/misc/mei/main.c | 18 ++++++++++++++----
> 3 files changed, 24 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/misc/mei/bus.c b/drivers/misc/mei/bus.c index
> 985bd4fd3328..5b2db77d48db 100644
> --- a/drivers/misc/mei/bus.c
> +++ b/drivers/misc/mei/bus.c
> @@ -66,9 +66,10 @@ ssize_t __mei_cl_send(struct mei_cl *cl, u8 *buf, size_t
> length,
>
> while (cl->tx_cb_queued >= bus->tx_queue_limit) {
> mutex_unlock(&bus->device_lock);
> - rets = wait_event_interruptible(cl->tx_wait,
> + rets = wait_event_interruptible_timeout(cl->tx_wait,
> cl->writing_state == MEI_WRITE_COMPLETE
> ||
> - (!mei_cl_is_connected(cl)));
> + !mei_cl_is_connected(cl),
> + HZ);
> mutex_lock(&bus->device_lock);
> if (rets) {
> if (signal_pending(current))
> @@ -79,6 +80,10 @@ ssize_t __mei_cl_send(struct mei_cl *cl, u8 *buf, size_t
> length,
> rets = -ENODEV;
> goto out;
> }
> + if (cl->writing_state != MEI_WRITE_COMPLETE) {
> + rets = -EFAULT;
> + goto out;
> + }
> }
>
> cb = mei_cl_alloc_cb(cl, length, MEI_FOP_WRITE, NULL); diff --git
> a/drivers/misc/mei/client.c b/drivers/misc/mei/client.c index
> 1e3edbbacb1e..e7acc8aa9b15 100644
> --- a/drivers/misc/mei/client.c
> +++ b/drivers/misc/mei/client.c
> @@ -1767,9 +1767,10 @@ ssize_t mei_cl_write(struct mei_cl *cl, struct
> mei_cl_cb *cb)
> if (blocking && cl->writing_state != MEI_WRITE_COMPLETE) {
>
> mutex_unlock(&dev->device_lock);
> - rets = wait_event_interruptible(cl->tx_wait,
> + rets = wait_event_interruptible_timeout(cl->tx_wait,
> cl->writing_state == MEI_WRITE_COMPLETE
> ||
> - (!mei_cl_is_connected(cl)));
> + !mei_cl_is_connected(cl),
> + HZ);
> mutex_lock(&dev->device_lock);
> /* wait_event_interruptible returns -ERESTARTSYS */
> if (rets) {
> diff --git a/drivers/misc/mei/main.c b/drivers/misc/mei/main.c index
> f894d1f8a53e..0eb7bfd89a90 100644
> --- a/drivers/misc/mei/main.c
> +++ b/drivers/misc/mei/main.c
> @@ -294,9 +294,10 @@ static ssize_t mei_write(struct file *file, const char
> __user *ubuf,
> goto out;
> }
> mutex_unlock(&dev->device_lock);
> - rets = wait_event_interruptible(cl->tx_wait,
> + rets = wait_event_interruptible_timeout(cl->tx_wait,
> cl->writing_state == MEI_WRITE_COMPLETE
> ||
> - (!mei_cl_is_connected(cl)));
> + !mei_cl_is_connected(cl),
> + HZ);
> mutex_lock(&dev->device_lock);
> if (rets) {
> if (signal_pending(current))
> @@ -307,6 +308,10 @@ static ssize_t mei_write(struct file *file, const char
> __user *ubuf,
> rets = -ENODEV;
> goto out;
> }
> + if (cl->writing_state != MEI_WRITE_COMPLETE) {
> + rets = -EFAULT;
> + goto out;
> + }
> }
>
> cb = mei_cl_alloc_cb(cl, length, MEI_FOP_WRITE, file); @@ -658,9
> +663,10 @@ static int mei_fsync(struct file *fp, loff_t start, loff_t end, int
> datasync)
>
> while (mei_cl_is_write_queued(cl)) {
> mutex_unlock(&dev->device_lock);
> - rets = wait_event_interruptible(cl->tx_wait,
> + rets = wait_event_interruptible_timeout(cl->tx_wait,
> cl->writing_state == MEI_WRITE_COMPLETE
> ||
> - !mei_cl_is_connected(cl));
> + !mei_cl_is_connected(cl),
> + HZ);
> mutex_lock(&dev->device_lock);
> if (rets) {
> if (signal_pending(current))
> @@ -671,6 +677,10 @@ static int mei_fsync(struct file *fp, loff_t start, loff_t
> end, int datasync)
> rets = -ENODEV;
> goto out;
> }
> + if (cl->writing_state != MEI_WRITE_COMPLETE) {
> + rets = -EFAULT;
> + goto out;
> + }
> }
> rets = 0;
> out:
> --
> 2.22.0