On Mon, Oct 10, 2022 at 08:34:30AM +0200, Ahmad Fatoum wrote:
> BootROM on the i.MX7 doesn't set the SMP bit when booted
> over serial download. This leads to vastly worse performance
> when doing memory-heavy operations in a USB-booted system,
> as the caches are not utilized. Example running md5sum over
> a 25M image in ramfs:
>
> without patch: 10796ms
> with patch: 457ms
>
> This issue isn't unique to the i.MX7, but exists for the i.MX6UL as
> well, which also has the Cortex-A7 as CPU. Like with
> imx6ul_cpu_lowlevel_init(), adapt imx7_cpu_lowlevel_init() to avoid this
> slow down.
>
> Signed-off-by: Ahmad Fatoum <a.fatoum@xxxxxxxxxxxxxx>
> Signed-off-by: Johannes Zink <j.zink@xxxxxxxxxxxxxx>
> ---
> v1 -> v2:
> - don't drop arm arm_cpu_lowlevel_init as cortex_a7_lowlevel_init
> does not call it (Marco)
> ---
> arch/arm/mach-imx/cpu_init.c | 1 +
> 1 file changed, 1 insertion(+)
Applied, thanks
Sascha
>
> diff --git a/arch/arm/mach-imx/cpu_init.c b/arch/arm/mach-imx/cpu_init.c
> index ea3621541979..3f16ca70ce26 100644
> --- a/arch/arm/mach-imx/cpu_init.c
> +++ b/arch/arm/mach-imx/cpu_init.c
> @@ -49,6 +49,7 @@ void imx6ul_cpu_lowlevel_init(void)
>
> void imx7_cpu_lowlevel_init(void)
> {
> + cortex_a7_lowlevel_init();
> arm_cpu_lowlevel_init();
> imx_cpu_timer_init(IOMEM(MX7_SYSCNT_CTRL_BASE_ADDR));
> }
> --
> 2.30.2
>
>
>
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