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Re: [Qemu-devel] [PATCH v2 11/21] aspeed/timer: Ensure positive muldiv d
From: |
Andrew Jeffery |
Subject: |
Re: [Qemu-devel] [PATCH v2 11/21] aspeed/timer: Ensure positive muldiv delta |
Date: |
Thu, 20 Jun 2019 11:35:49 +0930 |
User-agent: |
Cyrus-JMAP/3.1.6-666-gb2312fa-fmstable-20190614v4 |
On Wed, 19 Jun 2019, at 02:24, Cédric Le Goater wrote:
> From: Christian Svensson <address@hidden>
>
> If the host decrements the counter register that results in a negative
> delta. This is then passed to muldiv64 which only handles unsigned
> numbers resulting in bogus results.
>
> This fix ensures the delta being operated on is positive.
>
> Test case: kexec a kernel using aspeed_timer and it will freeze on the
> second bootup when the kernel initializes the timer. With this patch
> that no longer happens and the timer appears to run OK.
>
> Signed-off-by: Christian Svensson <address@hidden>
> Signed-off-by: Cédric Le Goater <address@hidden>
Reviewed-by: Andrew Jeffery <address@hidden>
> ---
> hw/timer/aspeed_timer.c | 6 +++++-
> 1 file changed, 5 insertions(+), 1 deletion(-)
>
> diff --git a/hw/timer/aspeed_timer.c b/hw/timer/aspeed_timer.c
> index 6501fa0768e7..1f0f1886fb2a 100644
> --- a/hw/timer/aspeed_timer.c
> +++ b/hw/timer/aspeed_timer.c
> @@ -275,7 +275,11 @@ static void
> aspeed_timer_set_value(AspeedTimerCtrlState *s, int timer, int reg,
> int64_t delta = (int64_t) value - (int64_t)
> calculate_ticks(t, now);
> uint32_t rate = calculate_rate(t);
>
> - t->start += muldiv64(delta, NANOSECONDS_PER_SECOND, rate);
> + if (delta >= 0) {
> + t->start += muldiv64(delta, NANOSECONDS_PER_SECOND, rate);
> + } else {
> + t->start -= muldiv64(-delta, NANOSECONDS_PER_SECOND, rate);
> + }
> aspeed_timer_mod(t);
> }
> break;
> --
> 2.21.0
>
>
- Re: [Qemu-devel] [PATCH v2 05/21] aspeed: introduce a configurable number of CPU per machine, (continued)
- [Qemu-devel] [PATCH v2 06/21] aspeed: add support for multiple NICs, Cédric Le Goater, 2019/06/18
- [Qemu-devel] [PATCH v2 08/21] aspeed/timer: Status register contains reload for stopped timer, Cédric Le Goater, 2019/06/18
- [Qemu-devel] [PATCH v2 07/21] aspeed/timer: Fix behaviour running Linux, Cédric Le Goater, 2019/06/18
- [Qemu-devel] [PATCH v2 09/21] aspeed/timer: Fix match calculations, Cédric Le Goater, 2019/06/18
- [Qemu-devel] [PATCH v2 10/21] aspeed/timer: Provide back-pressure information for short periods, Cédric Le Goater, 2019/06/18
- [Qemu-devel] [PATCH v2 11/21] aspeed/timer: Ensure positive muldiv delta, Cédric Le Goater, 2019/06/18
- [Qemu-devel] [PATCH v2 12/21] aspeed: remove the "ram" link, Cédric Le Goater, 2019/06/18
- [Qemu-devel] [PATCH v2 13/21] aspeed: add a RAM memory region container, Cédric Le Goater, 2019/06/18
- [Qemu-devel] [PATCH v2 14/21] aspeed/smc: add a 'sdram_base' property, Cédric Le Goater, 2019/06/18
- [Qemu-devel] [PATCH v2 15/21] aspeed/smc: add support for DMAs, Cédric Le Goater, 2019/06/18
- [Qemu-devel] [PATCH v2 18/21] aspeed/smc: Calculate checksum on normal DMA, Cédric Le Goater, 2019/06/18
- [Qemu-devel] [PATCH v2 17/21] aspeed/smc: inject errors in DMA checksum, Cédric Le Goater, 2019/06/18
- [Qemu-devel] [PATCH v2 16/21] aspeed/smc: add DMA calibration settings, Cédric Le Goater, 2019/06/18
- [Qemu-devel] [PATCH v2 19/21] aspeed: Add support for the swift-bmc board, Cédric Le Goater, 2019/06/18
- [Qemu-devel] [PATCH v2 20/21] hw/misc/aspeed_xdma: New device, Cédric Le Goater, 2019/06/18