On Fri, Oct 17, 2025 at 08:49:47PM +0530, Kaustabh Chakraborty wrote: > In devices where the U-Boot is used as a secondary bootloader, we rely > on the device's primary bootloader to implement CNTFRQ_EL0. However, > this reliance may lead to a non-functional timer in broken firmware. > > For instance, some versions of Samsung's S-Boot don't implement it. It's > also not possible to set it in the U-Boot, because it's booted in a lower > exception level. CNTFRQ_EL0 is reported to be 0. > > Use gd->arch.timer_rate_hz to override the queried value if set. This > setting needs to be done in the board file, preferrably in timer_init(). > > Signed-off-by: Kaustabh Chakraborty <[email protected]> > --- > Changes in v2: > - Switched to using gd->arch.timer_rate_hz instead of a new config > option (Ahmad Fatoum) > - Link to v1: > https://lore.kernel.org/r/[email protected] > --- > arch/arm/cpu/armv8/generic_timer.c | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/arch/arm/cpu/armv8/generic_timer.c > b/arch/arm/cpu/armv8/generic_timer.c > index > 1de7ec596fc7cbbc3e78a241f163bc0a4fcad6b6..1bc72ed26ca31af8e8e72008ed7885cbde23b076 > 100644 > --- a/arch/arm/cpu/armv8/generic_timer.c > +++ b/arch/arm/cpu/armv8/generic_timer.c > @@ -19,6 +19,10 @@ DECLARE_GLOBAL_DATA_PTR; > unsigned long notrace get_tbclk(void) > { > unsigned long cntfrq; > + > + if (gd->arch.timer_rate_hz) > + return gd->arch.timer_rate_hz; > + > asm volatile("mrs %0, cntfrq_el0" : "=r" (cntfrq)); > return cntfrq; > }
This would impact coreprimevelte (as it's the only ARM64 platform to set gd->arch.timer_rate_hz) but as it's also a Samsung platform it's likely in the same broken situation your platforms are. -- Tom
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