Atom processors use a 19.2 MHz crystal oscillator.
Early processors generate 100 MHz via 19.2 MHz * 26 / 5 = 99.84 MHz.
Later processors generate 100 MHz via 19.2 MHz * 125 / 24 = 100 MHz.
Update the Silvermont-based tables accordingly, matching the Software Developers Manual.
Also, correct a 166 MHz entry that should have been 116 MHz, and add a missing 80 MHz entry for VLV2.
This keeps in sync with Linux kernel commit: 05680e7: x86/tsc_msr: Correct Silvermont reference clock values
Signed-off-by: Bin Meng bmeng.cn@gmail.com ---
drivers/timer/tsc_timer.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/drivers/timer/tsc_timer.c b/drivers/timer/tsc_timer.c index 3c1b745..b242e74 100644 --- a/drivers/timer/tsc_timer.c +++ b/drivers/timer/tsc_timer.c @@ -44,11 +44,11 @@ static struct freq_desc freq_desc_tables[] = { /* CLV+ */ { 6, 0x35, 0, { 0, 133200, 0, 0, 0, 99840, 0, 83200 } }, /* TNG - Intel Atom processor Z3400 series */ - { 6, 0x4a, 1, { 0, 99840, 133200, 0, 0, 0, 0, 0 } }, + { 6, 0x4a, 1, { 0, 100000, 133300, 0, 0, 0, 0, 0 } }, /* VLV2 - Intel Atom processor E3000, Z3600, Z3700 series */ - { 6, 0x37, 1, { 83200, 99840, 133200, 166400, 0, 0, 0, 0 } }, + { 6, 0x37, 1, { 83300, 100000, 133300, 116700, 80000, 0, 0, 0 } }, /* ANN - Intel Atom processor Z3500 series */ - { 6, 0x5a, 1, { 83200, 99840, 133200, 99840, 0, 0, 0, 0 } }, + { 6, 0x5a, 1, { 83300, 100000, 133300, 100000, 0, 0, 0, 0 } }, /* Ivybridge */ { 6, 0x3a, 2, { 0, 0, 0, 0, 0, 0, 0, 0 } }, }; @@ -99,7 +99,7 @@ static unsigned long __maybe_unused try_msr_calibrate_tsc(void)
if (freq_desc_tables[cpu_index].msr_plat == 2) { /* TODO: Figure out how best to deal with this */ - freq = 99840; + freq = 100000; debug("Using frequency: %u KHz\n", freq); } else { /* Get FSB FREQ ID */