forked from Minki/linux
c7df1f4bda
The PCIe code has an array of buffer descriptors (RXBs) that have pages and DMA mappings attached. In regular use, the array isn't used and the buffers are either on the hardware receive queue or the rx_free/rx_used lists for recycling. Occasionally, during module unload, we'd see a warning from this: WARNING: at lib/list_debug.c:32 __list_add+0x91/0xa0() list_add corruption. prev->next should be next (c31c98cc), but was c31c80bc. (prev=c31c80bc). Pid: 519, comm: rmmod Tainted: G W O 3.4.24-dev #3 Call Trace: [<c10335b2>] warn_slowpath_common+0x72/0xa0 [<c1033683>] warn_slowpath_fmt+0x33/0x40 [<c12e31d1>] __list_add+0x91/0xa0 [<fdf2083c>] iwl_pcie_rxq_free_rbs+0xcc/0xe0 [iwlwifi] [<fdf21b3f>] iwl_pcie_rx_free+0x3f/0x210 [iwlwifi] [<fdf2dd7a>] iwl_trans_pcie_free+0x2a/0x90 [iwlwifi] The reason for this seems to be that in iwl_pcie_rxq_free_rbs() we use the array to free all buffers (the hardware receive queue isn't in use any more at this point). The function also adds all buffers to rx_used because it's also used during initialisation (when no freeing happens.) This can cause the warning because it may add entries to the list that are already on it. Luckily, this is harmless because it can only happen when the entire data structure is freed anyway, since during init both lists are initialized from scratch. Disentangle this code and treat init and free separately. During init we just need to put them onto the list after freeing all buffers (for switching between 4k/8k buffers); during free no list manipulations are necessary at all. Reviewed-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com> Signed-off-by: Johannes Berg <johannes.berg@intel.com> |
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| .. | ||
| appletalk | ||
| arcnet | ||
| bonding | ||
| caif | ||
| can | ||
| cris | ||
| dsa | ||
| ethernet | ||
| fddi | ||
| hamradio | ||
| hippi | ||
| hyperv | ||
| ieee802154 | ||
| irda | ||
| phy | ||
| plip | ||
| ppp | ||
| slip | ||
| team | ||
| usb | ||
| vmxnet3 | ||
| wan | ||
| wimax | ||
| wireless | ||
| xen-netback | ||
| dummy.c | ||
| eql.c | ||
| ifb.c | ||
| Kconfig | ||
| LICENSE.SRC | ||
| loopback.c | ||
| macvlan.c | ||
| macvtap.c | ||
| Makefile | ||
| mdio.c | ||
| mii.c | ||
| netconsole.c | ||
| ntb_netdev.c | ||
| rionet.c | ||
| sb1000.c | ||
| Space.c | ||
| sungem_phy.c | ||
| tun.c | ||
| veth.c | ||
| virtio_net.c | ||
| vxlan.c | ||
| xen-netfront.c | ||