| Message ID | 1478134585-454-1-git-send-email-andre.przywara@arm.com |
|---|---|
| State | Accepted |
| Commit | 68fd5c136cfdcbe6d96f38d0db29141af953af85 |
| Delegated to: | Tom Rini |
| Headers | show |
On Thu, Nov 03, 2016 at 12:56:25AM +0000, Andre Przywara wrote: > For 64-bit ARM systems we provide just a timer_read_counter() > implementation and rely on the generic non-uclass get_ticks() function > in lib/time.c to call the former. > However this function is actually not 64-bit safe, as it assumes a > "long" to be 32-bit. Beside the fact that the resulting uint64_t > isn't bigger than "long" on 64-bit architectures and thus combining two > counters makes no sense, we get all kind of weird results when we try > to OR in the high value shifted by _32_ bits. > So let's avoid that function at all and provide a straight forward > get_ticks() implementation for ARMv8, which also is in line with ARMv7. > > This fixes occasional immediate time-out expiration issues I see on the > Pine64 board. The root cause of this needs to be investigated, but this > fix looks like the right thing anyway. > > Signed-off-by: Andre Przywara <andre.przywara@arm.com> Applied to u-boot/master, thanks!
diff --git a/arch/arm/cpu/armv8/generic_timer.c b/arch/arm/cpu/armv8/generic_timer.c index 8f47a82..cd92b2c 100644 --- a/arch/arm/cpu/armv8/generic_timer.c +++ b/arch/arm/cpu/armv8/generic_timer.c @@ -9,6 +9,8 @@ #include <command.h> #include <asm/system.h> +DECLARE_GLOBAL_DATA_PTR; + /* * Generic timer implementation of get_tbclk() */ @@ -41,6 +43,15 @@ unsigned long timer_read_counter(void) return cntpct; } +unsigned long long get_ticks(void) +{ + unsigned long ticks = timer_read_counter(); + + gd->arch.tbl = ticks; + + return ticks; +} + unsigned long usec2ticks(unsigned long usec) { ulong ticks;
For 64-bit ARM systems we provide just a timer_read_counter() implementation and rely on the generic non-uclass get_ticks() function in lib/time.c to call the former. However this function is actually not 64-bit safe, as it assumes a "long" to be 32-bit. Beside the fact that the resulting uint64_t isn't bigger than "long" on 64-bit architectures and thus combining two counters makes no sense, we get all kind of weird results when we try to OR in the high value shifted by _32_ bits. So let's avoid that function at all and provide a straight forward get_ticks() implementation for ARMv8, which also is in line with ARMv7. This fixes occasional immediate time-out expiration issues I see on the Pine64 board. The root cause of this needs to be investigated, but this fix looks like the right thing anyway. Signed-off-by: Andre Przywara <andre.przywara@arm.com> --- arch/arm/cpu/armv8/generic_timer.c | 11 +++++++++++ 1 file changed, 11 insertions(+)