[PATCH v2 1/2] intel_idle: re-work bxt_idle_state_table_update() and its helper
From: Jan Beulich <hidden>
Date: 2016-06-27 06:35:16
Since irtl_ns_units[] has itself zero entries, make sure the caller recognized those cases along with the MSR read returning zero, as zero is not a valid value for exit_latency and target_residency. Signed-off-by: Jan Beulich <redacted> --- drivers/idle/intel_idle.c | 29 ++++++++++++++--------------- 1 file changed, 14 insertions(+), 15 deletions(-)
--- 4.7-rc5-intel-idle-BXT.orig/drivers/idle/intel_idle.c
+++ 4.7-rc5-intel-idle-BXT/drivers/idle/intel_idle.c@@ -1154,6 +1154,9 @@ static unsigned long long irtl_2_usec(un { unsigned long long ns; + if (!irtl) + return 0; + ns = irtl_ns_units[(irtl >> 10) & 0x3]; return div64_u64((irtl & 0x3FF) * ns, 1000);
@@ -1167,43 +1170,39 @@ static unsigned long long irtl_2_usec(un static void bxt_idle_state_table_update(void) { unsigned long long msr; + unsigned int usec; rdmsrl(MSR_PKGC6_IRTL, msr); - if (msr) { - unsigned int usec = irtl_2_usec(msr); - + usec = irtl_2_usec(msr); + if (usec) { bxt_cstates[2].exit_latency = usec; bxt_cstates[2].target_residency = usec; } rdmsrl(MSR_PKGC7_IRTL, msr); - if (msr) { - unsigned int usec = irtl_2_usec(msr); - + usec = irtl_2_usec(msr); + if (usec) { bxt_cstates[3].exit_latency = usec; bxt_cstates[3].target_residency = usec; } rdmsrl(MSR_PKGC8_IRTL, msr); - if (msr) { - unsigned int usec = irtl_2_usec(msr); - + usec = irtl_2_usec(msr); + if (usec) { bxt_cstates[4].exit_latency = usec; bxt_cstates[4].target_residency = usec; } rdmsrl(MSR_PKGC9_IRTL, msr); - if (msr) { - unsigned int usec = irtl_2_usec(msr); - + usec = irtl_2_usec(msr); + if (usec) { bxt_cstates[5].exit_latency = usec; bxt_cstates[5].target_residency = usec; } rdmsrl(MSR_PKGC10_IRTL, msr); - if (msr) { - unsigned int usec = irtl_2_usec(msr); - + usec = irtl_2_usec(msr); + if (usec) { bxt_cstates[6].exit_latency = usec; bxt_cstates[6].target_residency = usec; }