The reset count was only decremented if the device was in a single
reset.
Also move the decrement before calling the exit phase method to fix
problem of reset state evaluation during that call. Update the doc
accordingly.
Signed-off-by: Damien Hedde <damien.he...@greensocs.com>
Fixes: 1905297 ("Zynq7000 UART clock reset initialization", 2020-11-23)
Reported-by: Michael Peter <michael.pe...@hensoldt-cyber.com>
--
Hi all,
While looking at the bug reported by Michael and his patch. I found another
bug. Apparently I forgot to decrement the reset count if there was several
reset at the same time.
This patch fixes that.
I also moved the place of the decrement: before calling the exit phase method.
it globally fixes Michael's reported bug, as I think it will avoid some boiler
plate code in every exit phase method we do.
Only other place where the reset state is checked is in the
hw/char/cadence-uart.c so it does not have high impact.
I'm not sure if this meets the condition for 5.2 as it changes a documented
feature. In that case we can just accept Michael solution and I'll fix the
rest later.
Here's the pointer for the bug and michael's patch.
https://lists.nongnu.org/archive/html/qemu-devel/2020-11/msg05786.html
https://lists.nongnu.org/archive/html/qemu-devel/2020-11/msg06105.html
Damien
---
docs/devel/reset.rst | 6 +++---
hw/core/resettable.c | 3 +--
2 files changed, 4 insertions(+), 5 deletions(-)
diff --git a/docs/devel/reset.rst b/docs/devel/reset.rst
index abea1102dc..021a7277a2 100644
--- a/docs/devel/reset.rst
+++ b/docs/devel/reset.rst
@@ -210,9 +210,9 @@ Polling the reset state
Resettable interface provides the ``resettable_is_in_reset()`` function.
This function returns true if the object parameter is currently under reset.
-An object is under reset from the beginning of the *init* phase to the end of
-the *exit* phase. During all three phases, the function will return that the
-object is in reset.
+An object is under reset from the beginning of the *init* phase to the *exit*
+phase. During *init* and *hold* phase only, the function will return that the
+object is in reset. The state is changed just before calling the *exit* method.
This function may be used if the object behavior has to be adapted
while in reset state. For example if a device has an irq input,
diff --git a/hw/core/resettable.c b/hw/core/resettable.c
index 96a99ce39e..c3df75c6ba 100644
--- a/hw/core/resettable.c
+++ b/hw/core/resettable.c
@@ -201,12 +201,11 @@ static void resettable_phase_exit(Object *obj, void
*opaque, ResetType type)
resettable_child_foreach(rc, obj, resettable_phase_exit, NULL, type);
assert(s->count > 0);
- if (s->count == 1) {
+ if (--s->count == 0) {
trace_resettable_phase_exit_exec(obj, obj_typename, !!rc->phases.exit);
if (rc->phases.exit && !resettable_get_tr_func(rc, obj)) {
rc->phases.exit(obj);
}
- s->count = 0;
}
s->exit_phase_in_progress = false;
trace_resettable_phase_exit_end(obj, obj_typename, s->count);
--
2.29.2
