Current QEMU doesn't clear PL061 state after reset. This causes a weird issue with guest reboot via GPIO. Here is the device state description with two reboot requests:
(PL061State fields) data old_in_data istate VM boot 0 0 0 After 1st ACPI reboot request 8 8 8 After VM PL061 driver ACK 8 8 0 After VM reboot 8 8 0 ------------------------------------------------------------ 2nd ACPI reboot request 8 In the second reboot request above, because old_in_data field is 8, QEMU decides that there is a pending edge IRQ already (see pl061_update()) in input; so it doesn't raise up IRQ again. As a result the second reboot request is lost. The correct way is to clear PL061 device state after reset. NOTE: The reset state is found from the following documentation: - PL061 Technical Reference Manual - Stellaris LM3S8962 Microcontroller Data Sheet - Stellaris LM3S5P31 Microcontroller Data Sheet Signed-off-by: Wei Huang <w...@redhat.com> --- hw/gpio/pl061.c | 32 ++++++++++++++++++++++++++++++-- 1 file changed, 30 insertions(+), 2 deletions(-) diff --git a/hw/gpio/pl061.c b/hw/gpio/pl061.c index e5a696e..342a70d 100644 --- a/hw/gpio/pl061.c +++ b/hw/gpio/pl061.c @@ -284,8 +284,35 @@ static void pl061_write(void *opaque, hwaddr offset, static void pl061_reset(PL061State *s) { - s->locked = 1; - s->cr = 0xff; + /* reset values from PL061 TRM, Stellaris LM3S5P31 & LM3S8962 Data Sheet */ + s->data = 0; + s->old_out_data = 0; + s->old_in_data = 0; + s->dir = 0; + s->isense = 0; + s->ibe = 0; + s->iev = 0; + s->im = 0; + s->istate = 0; + s->afsel = 0; + s->dr2r = 0xff; + s->dr4r = 0; + s->dr8r = 0; + s->odr = 0; + s->pur = 0; + s->pdr = 0; + s->slr = 0; + s->den = 0; + s->locked = 1; + s->cr = 0xff; + s->amsel = 0; +} + +static void pl061_state_reset(DeviceState *dev) +{ + PL061State *s = PL061(dev); + + pl061_reset(s); } static void pl061_set_irq(void * opaque, int irq, int level) @@ -343,6 +370,7 @@ static void pl061_class_init(ObjectClass *klass, void *data) k->init = pl061_initfn; dc->vmsd = &vmstate_pl061; + dc->reset = &pl061_state_reset; } static const TypeInfo pl061_info = { -- 1.8.3.1