diff options
Diffstat (limited to '0001-e1000e-Fix-tight-loop-implementation-of-systime-read.patch')
| -rw-r--r-- | 0001-e1000e-Fix-tight-loop-implementation-of-systime-read.patch | 65 |
1 files changed, 0 insertions, 65 deletions
diff --git a/0001-e1000e-Fix-tight-loop-implementation-of-systime-read.patch b/0001-e1000e-Fix-tight-loop-implementation-of-systime-read.patch deleted file mode 100644 index 0bea7fe08cd4..000000000000 --- a/0001-e1000e-Fix-tight-loop-implementation-of-systime-read.patch +++ /dev/null @@ -1,65 +0,0 @@ -From 37b12910dd11d9ab969f2c310dc9160b7f3e3405 Mon Sep 17 00:00:00 2001 -From: Raanan Avargil <raanan.avargil@intel.com> -Date: Sun, 19 Jul 2015 16:33:20 +0300 -Subject: [PATCH] e1000e: Fix tight loop implementation of systime read - algorithm - -Change the algorithm. Read systimel twice and check for overflow. -If there was no overflow, use the first value. -If there was an overflow, read systimeh again and use the second -systimel value. - -Signed-off-by: Raanan Avargil <raanan.avargil@intel.com> -Tested-by: Aaron Brown <aaron.f.brown@intel.com> -Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com> ---- - drivers/net/ethernet/intel/e1000e/netdev.c | 31 ++++++++++++++++++++---------- - 1 file changed, 21 insertions(+), 10 deletions(-) - -diff --git a/drivers/net/ethernet/intel/e1000e/netdev.c b/drivers/net/ethernet/intel/e1000e/netdev.c -index 24b7269..96a8166 100644 ---- a/drivers/net/ethernet/intel/e1000e/netdev.c -+++ b/drivers/net/ethernet/intel/e1000e/netdev.c -@@ -4280,18 +4280,29 @@ static cycle_t e1000e_cyclecounter_read(const struct cyclecounter *cc) - struct e1000_adapter *adapter = container_of(cc, struct e1000_adapter, - cc); - struct e1000_hw *hw = &adapter->hw; -+ u32 systimel_1, systimel_2, systimeh; - cycle_t systim, systim_next; -- /* SYSTIMH latching upon SYSTIML read does not work well. To fix that -- * we don't want to allow overflow of SYSTIML and a change to SYSTIMH -- * to occur between reads, so if we read a vale close to overflow, we -- * wait for overflow to occur and read both registers when its safe. -+ /* SYSTIMH latching upon SYSTIML read does not work well. -+ * This means that if SYSTIML overflows after we read it but before -+ * we read SYSTIMH, the value of SYSTIMH has been incremented and we -+ * will experience a huge non linear increment in the systime value -+ * to fix that we test for overflow and if true, we re-read systime. - */ -- u32 systim_overflow_latch_fix = 0x3FFFFFFF; -- -- do { -- systim = (cycle_t)er32(SYSTIML); -- } while (systim > systim_overflow_latch_fix); -- systim |= (cycle_t)er32(SYSTIMH) << 32; -+ systimel_1 = er32(SYSTIML); -+ systimeh = er32(SYSTIMH); -+ systimel_2 = er32(SYSTIML); -+ /* Check for overflow. If there was no overflow, use the values */ -+ if (systimel_1 < systimel_2) { -+ systim = (cycle_t)systimel_1; -+ systim |= (cycle_t)systimeh << 32; -+ } else { -+ /* There was an overflow, read again SYSTIMH, and use -+ * systimel_2 -+ */ -+ systimeh = er32(SYSTIMH); -+ systim = (cycle_t)systimel_2; -+ systim |= (cycle_t)systimeh << 32; -+ } - - if ((hw->mac.type == e1000_82574) || (hw->mac.type == e1000_82583)) { - u64 incvalue, time_delta, rem, temp; --- -2.5.1 - |