[PATCH v2 2/6] iommu/sun50i: Track masters attached to the domain

[Jernej Škrabec]

Dne torek, 03. januar 2023 ob 02:08:59 CET je Samuel Holland napisal(a):
> The refcount logic here is broken. The refcount is initialized to 1 with
> no devices attached, so it will be decremented back to 1 when the last
> device is detached. However, refcount_dec_and_test() returns true only
> when the refcount gets decremented to zero, so the domain will never be
> cleaned up, and the hardware will never be disabled.
> 
> Replace the refcount with a mask of masters attached to the domain. The
> domain can be cleaned up when the last master detaches. This mask is
> also necessary to correctly set the bypass register.
> 
> Fixes: 4100b8c229b3 ("iommu: Add Allwinner H6 IOMMU driver")
> Signed-off-by: Samuel Holland <samuel at sholland.org>

Reviewed-by: Jernej Skrabec <jernej.skrabec at gmail.com>

Best regards,
Jernej