bb3afda4fc
The Flower app may receive a request to update the MTU of a representor netdev upon receipt of a control message from the firmware. This requires the RTNL lock which needs to be taken outside of the packet processing path. As a handling of this correctly seems a little to invasive for a fix simply skip setting the MTU for now. Relevant backtrace: [ 1496.288489] BUG: scheduling while atomic: kworker/0:3/373/0x00000100 [ 1496.294911] dca syscopyarea sysfillrect sysimgblt fb_sys_fops ptp drm mxm_wmi ahci pps_core libahci i2c_algo_bit wmi [last unloaded: nfp] [ 1496.294918] CPU: 0 PID: 373 Comm: kworker/0:3 Tainted: G OE 4.13.0-rc3+ #3 [ 1496.294919] Hardware name: Supermicro X10DRi/X10DRi, BIOS 2.0 12/28/2015 [ 1496.294923] Workqueue: events work_for_cpu_fn [ 1496.294924] Call Trace: [ 1496.294927] <IRQ> [ 1496.294931] dump_stack+0x63/0x82 [ 1496.294935] __schedule_bug+0x54/0x70 [ 1496.294937] __schedule+0x62f/0x890 [ 1496.294941] ? intel_unmap_sg+0x90/0x90 [ 1496.294942] schedule+0x36/0x80 [ 1496.294943] schedule_preempt_disabled+0xe/0x10 [ 1496.294945] __mutex_lock.isra.2+0x445/0x4a0 [ 1496.294947] ? device_is_rmrr_locked+0x12/0x50 [ 1496.294950] ? kfree+0x162/0x170 [ 1496.294952] ? device_is_rmrr_locked+0x12/0x50 [ 1496.294953] ? iommu_should_identity_map+0x50/0xe0 [ 1496.294954] __mutex_lock_slowpath+0x13/0x20 [ 1496.294955] ? iommu_no_mapping+0x48/0xd0 [ 1496.294956] ? __mutex_lock_slowpath+0x13/0x20 [ 1496.294957] mutex_lock+0x2f/0x40 [ 1496.294960] rtnl_lock+0x15/0x20 [ 1496.294979] nfp_flower_cmsg_rx+0xc8/0x150 [nfp] [ 1496.294986] nfp_ctrl_poll+0x286/0x350 [nfp] [ 1496.294989] tasklet_action+0xf6/0x110 [ 1496.294992] __do_softirq+0xed/0x278 [ 1496.294993] irq_exit+0xb6/0xc0 [ 1496.294994] do_IRQ+0x4f/0xd0 [ 1496.294996] common_interrupt+0x89/0x89 Fixes: 948faa46c05b ("nfp: add support for control messages for flower app") Signed-off-by: Simon Horman <simon.horman@netronome.com> Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Linux kernel ============ This file was moved to Documentation/admin-guide/README.rst Please notice that there are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. There are various text files in the Documentation/ subdirectory, several of them using the Restructured Text markup notation. See Documentation/00-INDEX for a list of what is contained in each file. Please read the Documentation/process/changes.rst file, as it contains the requirements for building and running the kernel, and information about the problems which may result by upgrading your kernel.