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| author | York Sun <yorksun@freescale.com> | 2015-03-20 19:28:05 -0700 |
|---|---|---|
| committer | York Sun <yorksun@freescale.com> | 2015-04-23 08:55:54 -0700 |
| commit | 060ef094600373ea2b25111006edc56c072d9bd7 (patch) | |
| tree | c43903ed0168ea3d2790da49fc674f9550d080e8 /arch/arm/cpu/armv8 | |
| parent | 5abf13e48a818eeb44cd236c3d3de79a0df59fac (diff) | |
| download | u-boot-imx-060ef094600373ea2b25111006edc56c072d9bd7.zip u-boot-imx-060ef094600373ea2b25111006edc56c072d9bd7.tar.gz u-boot-imx-060ef094600373ea2b25111006edc56c072d9bd7.tar.bz2 | |
armv8/fsl-lsch3: Implement workaround for erratum A008585
Generic Timer may contain an erroneous value. The workaround is to
read it twice until getting the same value.
Signed-off-by: York Sun <yorksun@freescale.com>
Diffstat (limited to 'arch/arm/cpu/armv8')
| -rw-r--r-- | arch/arm/cpu/armv8/generic_timer.c | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/arch/arm/cpu/armv8/generic_timer.c b/arch/arm/cpu/armv8/generic_timer.c index 223b95e..8e60bae 100644 --- a/arch/arm/cpu/armv8/generic_timer.c +++ b/arch/arm/cpu/armv8/generic_timer.c @@ -25,7 +25,18 @@ unsigned long get_tbclk(void) unsigned long timer_read_counter(void) { unsigned long cntpct; +#ifdef CONFIG_SYS_FSL_ERRATUM_A008585 + /* This erratum number needs to be confirmed to match ARM document */ + unsigned long temp; +#endif isb(); asm volatile("mrs %0, cntpct_el0" : "=r" (cntpct)); +#ifdef CONFIG_SYS_FSL_ERRATUM_A008585 + asm volatile("mrs %0, cntpct_el0" : "=r" (temp)); + while (temp != cntpct) { + asm volatile("mrs %0, cntpct_el0" : "=r" (cntpct)); + asm volatile("mrs %0, cntpct_el0" : "=r" (temp)); + } +#endif return cntpct; } |