Hi Mark, Rob, Frank, On Wed, Nov 28, 2018 at 10:28 AM Geert Uytterhoeven <geert@xxxxxxxxxxxxxx> wrote: > On Tue, Nov 13, 2018 at 2:35 PM Geert Uytterhoeven > <geert+renesas@xxxxxxxxx> wrote: > > In some SoCs multiple hardware blocks may share a reset control. > > The reset control API for shared resets will only assert such a reset > > when the drivers for all hardware blocks agree. > > The exclusive reset control API still allows to assert such a reset, but > > that impacts all other hardware blocks sharing the reset. > > > > While the kernel doc comments clearly state that the API for shared > > resets applies to reset controls which are shared between hardware > > blocks, the exact meaning of exclusive resets is not documented. > > Fix the semantic ambiguity with respect to exclusive access vs. > > exclusive reset lines by: > > 1. Clarifying that exclusive resets really are intended for use with > > reset controls which are dedicated to a single hardware block, > > 2. Ensuring that obtaining an exclusive reset control will fail if the > > reset is shared by multiple hardware blocks, for both DT-based and > > lookup-based reset controls. > > > > Signed-off-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx> > > --- > > Question from Philipp for the DT maintainers: > > > > "I'd still like to hear the device tree maintainers' opinion on > > parsing the whole DT for "resets" phandle properties to find shared > > resets like this." > > Mark, Rob: Ping? Do you have any comments about this? (In case you lost the link to the original patch: https://lore.kernel.org/lkml/20181113133520.20889-1-geert+renesas@xxxxxxxxx/). This is a safeguard dependency for "[PATCH v5] vfio: platform: Add generic reset controller support" (https://lore.kernel.org/lkml/20181113131508.18246-1-geert+renesas@xxxxxxxxx/). Thanks! Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds
