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authorGovindarajulu Varadarajan <_govind@gmx.com>2015-06-11 11:52:54 +0530
committerDavid S. Miller <davem@davemloft.net>2015-06-10 23:42:39 -0700
commit6286e8285078ab02b215bba1d42a05ecfd864515 (patch)
tree67d02668d9a1a519b5566d25ca281178f4566525
parent5d753610277862fd8050901f38b6571b9500cdb6 (diff)
downloadlinux-linaro-stable-6286e8285078ab02b215bba1d42a05ecfd864515.tar.gz
enic: unlock napi busy poll before unmasking intr
There is a small window between vnic_intr_unmask() and enic_poll_unlock_napi(). In this window if an irq occurs and napi is scheduled on different cpu, it tries to acquire enic_poll_lock_napi() and hits the following WARN_ON message. Fix is to unlock napi_poll before unmasking the interrupt. [ 781.121746] ------------[ cut here ]------------ [ 781.121789] WARNING: CPU: 1 PID: 0 at drivers/net/ethernet/cisco/enic/vnic_rq.h:228 enic_poll_msix_rq+0x36a/0x3c0 [enic]() [ 781.121834] Modules linked in: nfsv3 nfs_acl rpcsec_gss_krb5 auth_rpcgss oid_registry nfsv4 dns_resolver coretemp intel_rapl iosf_mbi x86_pkg_temp_thermal intel_powerclamp kvm_intel kvm crct10dif_pclmul crc32_pclmul ghash_clmulni_intel aesni_intel mgag200 ttm drm_kms_helper joydev aes_x86_64 lrw drm gf128mul mousedev glue_helper sb_edac ablk_helper iTCO_wdt iTCO_vendor_support evdev ipmi_si syscopyarea sysfillrect sysimgblt i2c_algo_bit i2c_core edac_core lpc_ich mac_hid cryptd pcspkr ipmi_msghandler shpchp tpm_tis acpi_power_meter tpm wmi processor hwmon button ac sch_fq_codel nfs lockd grace sunrpc fscache hid_generic usbhid hid ehci_pci ehci_hcd sd_mod megaraid_sas usbcore scsi_mod usb_common enic crc32c_generic crc32c_intel btrfs xor raid6_pq ext4 crc16 mbcache jbd2 [ 781.122176] CPU: 1 PID: 0 Comm: swapper/1 Not tainted 4.1.0-rc6-ARCH-00040-gc46a024-dirty #106 [ 781.122210] Hardware name: Cisco Systems Inc UCSB-B200-M4/UCSB-B200-M4, BIOS B200M4.2.2.2.23.061220140128 06/12/2014 [ 781.122252] 0000000000000000 bddbbc9d655ec96e ffff880277e43da8 ffffffff81583fe8 [ 781.122286] 0000000000000000 0000000000000000 ffff880277e43de8 ffffffff8107acfa [ 781.122319] ffff880272c01000 ffff880273f18000 ffff880273f1a100 0000000000000000 [ 781.122352] Call Trace: [ 781.122364] <IRQ> [<ffffffff81583fe8>] dump_stack+0x4f/0x7b [ 781.122399] [<ffffffff8107acfa>] warn_slowpath_common+0x8a/0xc0 [ 781.122425] [<ffffffff8107ae2a>] warn_slowpath_null+0x1a/0x20 [ 781.122455] [<ffffffffa01fa9ca>] enic_poll_msix_rq+0x36a/0x3c0 [enic] [ 781.122487] [<ffffffff8148525a>] net_rx_action+0x22a/0x370 [ 781.122512] [<ffffffff8107ed3d>] __do_softirq+0xed/0x2d0 [ 781.122537] [<ffffffff8107f06e>] irq_exit+0x7e/0xa0 [ 781.122560] [<ffffffff8158c424>] do_IRQ+0x64/0x100 [ 781.122582] [<ffffffff8158a42e>] common_interrupt+0x6e/0x6e [ 781.122605] <EOI> [<ffffffff810bd331>] ? cpu_startup_entry+0x121/0x480 [ 781.122638] [<ffffffff810bd2fc>] ? cpu_startup_entry+0xec/0x480 [ 781.122667] [<ffffffff810f2ed3>] ? clockevents_register_device+0x113/0x1f0 [ 781.122698] [<ffffffff81050ab6>] start_secondary+0x196/0x1e0 [ 781.122723] ---[ end trace cec2e9dd3af7b9db ]--- Signed-off-by: Govindarajulu Varadarajan <_govind@gmx.com> Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--drivers/net/ethernet/cisco/enic/enic_main.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/net/ethernet/cisco/enic/enic_main.c b/drivers/net/ethernet/cisco/enic/enic_main.c
index 204bd182..0e5a01d 100644
--- a/drivers/net/ethernet/cisco/enic/enic_main.c
+++ b/drivers/net/ethernet/cisco/enic/enic_main.c
@@ -1407,6 +1407,7 @@ static int enic_poll_msix_rq(struct napi_struct *napi, int budget)
*/
enic_calc_int_moderation(enic, &enic->rq[rq]);
+ enic_poll_unlock_napi(&enic->rq[rq]);
if (work_done < work_to_do) {
/* Some work done, but not enough to stay in polling,
@@ -1418,7 +1419,6 @@ static int enic_poll_msix_rq(struct napi_struct *napi, int budget)
enic_set_int_moderation(enic, &enic->rq[rq]);
vnic_intr_unmask(&enic->intr[intr]);
}
- enic_poll_unlock_napi(&enic->rq[rq]);
return work_done;
}