Re: [PATCH v7 17/23] scsi: ufs: mediatek: Rework ufs_mtk_wait_idle_state

On Mon, 2026-02-16 at 14:37 +0100, Nicolas Frattaroli wrote:

While ufs_mtk_wait_idle state has some code smells for me (the
VS_HCE_BASE early exit seems racey at best), it can still benefit
from
some general cleanup to make the code flow less convoluted.

Use the iopoll helpers, for one, and specifically the one that sleeps
and does not busy delay, as it's being done for up to 5ms.

The register read is split out to a helper function that branches
between new and old style flow.

Every called uses the same 5ms timeout value, so there is no point in
making this a parameter. Just assume a 5ms timeout in the function.

Reviewed-by: AngeloGioacchino Del Regno
[off-list ref]
Signed-off-by: Nicolas Frattaroli <nicolas.frattaroli@collabora.com>

Hi Nicolas,

The logic is quite different.

Previously, the check was:
If (sm >= VS_HIB_ENTER) and (sm <= VS_HIB_EXIT), then wait for sm to
reach VS_HCE_BASE.
If not ((val < VS_HIB_ENTER) and (val > VS_HIB_EXIT)), then exit the
loop directly.

Now, the logic is:
If sm == VS_HCE_BASE, return 0.
If (sm >= VS_HIB_ENTER) and (sm <= VS_HIB_EXIT), then wait for sm to 
transition to any other state and exit the poll.

Thanks
Peter