Bernhard Kaindl 7acf631889 igb: remove blocking phy read from inside spinlock ... Remove a source of latency spikes (in my case up to 10ms) by not calling code that uses mdelay() for feeding a phy statistic (rx errors for idle symbols - not data -> idle_errors) while being called with a spinlock held. As idle_errors isn't read, this patch only removes unused code and data. Later, more complicated changes may be applied to address the spinlock and allow for some PHY diagnostics by harvesting this PHY stats register fully. This patch is designed to fix the issue and be safe for longterm/stable. For the Intel e1000e driver, the same change was applied in 2008 with commit 23033fad5b ("e1000e: remove phy read from inside spinlock"). The mdelay is triggered by HW/SW semaphores, thus it depends on the HW. I've HW that triggers it even when idle. Others may trigger it only e.g. when Ethernet ports aquire or loose the link or on ifconfig up / down. We've noticed this first from delays in frame rx/tx due to the mdelay(). Example command for checking if the issue is triggered: cyclictest -Smp1 (Look for occasional "Max:" values > 4000 or use -b 4000 to stop if greater) It was observed with I350 ports connected to other I350 ports, but not if driver and EEPROM was modified to run the I350 in EEPROM-less mode. phy_stats.idle_errors and .receive_errors (isn't touched) occupy 64 not used bits in the adapter struct: Their allocation may be removed as well. Cc: Carolyn Wyborny <carolyn.wyborny@intel.com> Cc: Todd Fujinaka <todd.fujinaka@intel.com> Fixes: 12dcd86b75 ("igb: fix stats handling") (this added the spin_lock) Signed-off-by: Bernhard Kaindl <bk-linux@use.startmail.com> Tested-by: Aaron Brown <aaron.f.brown@intel.com> Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>		2014-10-02 02:30:39 -07:00
..
e1000	e1000: switch to napi_gro_frags api	2014-09-12 02:24:49 -07:00
e1000e	e1000e: Fix TSO with non-accelerated vlans	2014-08-25 17:27:09 -07:00
fm10k	fm10k: Correctly set the number of Tx queues	2014-10-01 23:42:55 -07:00
i40e	Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net	2014-09-07 21:41:53 -07:00
i40evf	Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net	2014-09-07 21:41:53 -07:00
igb	igb: remove blocking phy read from inside spinlock	2014-10-02 02:30:39 -07:00
igbvf	PCI: Remove DEFINE_PCI_DEVICE_TABLE macro use	2014-08-12 12:15:14 -06:00
ixgb	PCI: Remove DEFINE_PCI_DEVICE_TABLE macro use	2014-08-12 12:15:14 -06:00
ixgbe	ixgbe: delete one duplicate marcro definition of IXGBE_MAX_L2A_QUEUES	2014-10-02 02:24:08 -07:00
ixgbevf	ixgbevf: remove useless bd_number from struct ixgbevf_adapter	2014-09-18 02:59:27 -07:00
e100.c	PCI: Remove DEFINE_PCI_DEVICE_TABLE macro use	2014-08-12 12:15:14 -06:00
Kconfig	fm10k: Add skeletal frame for Intel(R) FM10000 Ethernet Switch Host Interface Driver	2014-09-23 03:59:13 -07:00
Makefile	fm10k: Add skeletal frame for Intel(R) FM10000 Ethernet Switch Host Interface Driver	2014-09-23 03:59:13 -07:00