* Julien Panis <jpanis@xxxxxxxxxxxx> [230821 14:24]:
> The am335x-evm started producing boot errors because of subtle timing
> changes:
>
> Unhandled fault: external abort on non-linefetch (0x1008) at 0xf03c1010
> ...
> sysc_reset from sysc_probe+0xf60/0x1514
> sysc_probe from platform_probe+0x5c/0xbc
> ...
>
> The fix consists in using the appropriate sleep function in sysc reset.
> For flexible sleeping, fsleep is recommended. Here, sysc delay parameter
> can take any value in [0 - 255] us range. As a result, fsleep() should
> be used, calling udelay() for a sysc delay lower than 10 us.
>
> Signed-off-by: Julien Panis <jpanis@xxxxxxxxxxxx>
> Fixes: e709ed70d122 ("bus: ti-sysc: Fix missing reset delay handling")
> ---
> Fix boot errors for am335x-evm in sysc_reset(), by using fsleep() instead
> of usleep_range() function. Thus, udelay() will be called if the configured
> sysc delay is lower than 10 us (which is usually the case, since the value
> set in the device tree is currently 2 us).
OK, interesting. Yeah I've only ever seen values of 2 us needed here.
Regards,
Tony
> ---
> drivers/bus/ti-sysc.c | 3 +--
> 1 file changed, 1 insertion(+), 2 deletions(-)
>
> diff --git a/drivers/bus/ti-sysc.c b/drivers/bus/ti-sysc.c
> index 4cb23b9e06ea..59b8bdd9203e 100644
> --- a/drivers/bus/ti-sysc.c
> +++ b/drivers/bus/ti-sysc.c
> @@ -2147,8 +2147,7 @@ static int sysc_reset(struct sysc *ddata)
> }
>
> if (ddata->cfg.srst_udelay)
> - usleep_range(ddata->cfg.srst_udelay,
> - ddata->cfg.srst_udelay * 2);
> + fsleep(ddata->cfg.srst_udelay);
>
> if (ddata->post_reset_quirk)
> ddata->post_reset_quirk(ddata);
>
> ---
> base-commit: f7757129e3dea336c407551c98f50057c22bb266
> change-id: 20230821-fix-ti-sysc-reset-5c164051345b
>
> Best regards,
> --
> Julien Panis <jpanis@xxxxxxxxxxxx>
>
