On 7/17/19 12:15 AM, Philippe Mathieu-Daudé wrote: > A "system reset" sets the device state machine in READ_ARRAY mode > and, after some delay, set the SR.7 READY bit. > > We do not model timings, so we set the SR.7 bit directly. > > The TYPE_DEVICE interface provides a DeviceReset handler. > This pflash device is a subclass of TYPE_SYS_BUS_DEVICE (which > is a subclass of TYPE_DEVICE). > SYS_BUS devices are automatically plugged into the 'main system > bus', which is the root of the qbus tree. > Devices in the qbus tree are guaranteed to have their reset() > handler called after realize() and before we try to run the guest. > > To avoid incoherent states when the machine resets (see but report
"bug report" > below), factor out the reset code into pflash_cfi01_system_reset, > and register the method as a device reset callback. > > Buglink: https://bugzilla.redhat.com/show_bug.cgi?id=1678713 > Reported-by: Laszlo Ersek <ler...@redhat.com> > Reviewed-by: John Snow <js...@redhat.com> > Reviewed-by: Alistair Francis <alistair.fran...@wdc.com> > Signed-off-by: Philippe Mathieu-Daudé <phi...@redhat.com> > --- > v6: dropped Laszlo's Regression-tested-by tag > --- > hw/block/pflash_cfi01.c | 15 +++++++++++++-- > 1 file changed, 13 insertions(+), 2 deletions(-) > > diff --git a/hw/block/pflash_cfi01.c b/hw/block/pflash_cfi01.c > index 65afdbf3a7..ee0ed70242 100644 > --- a/hw/block/pflash_cfi01.c > +++ b/hw/block/pflash_cfi01.c > @@ -768,8 +768,6 @@ static void pflash_cfi01_realize(DeviceState *dev, Error > **errp) > pfl->max_device_width = pfl->device_width; > } > > - pflash_mode_read_array(pfl); > - pfl->status = 0x80; /* WSM ready */ > /* Hardcoded CFI table */ > /* Standard "QRY" string */ > pfl->cfi_table[0x10] = 'Q'; > @@ -857,6 +855,18 @@ static void pflash_cfi01_realize(DeviceState *dev, Error > **errp) > pfl->cfi_table[0x3f] = 0x01; /* Number of protection fields */ > } > > +static void pflash_cfi01_system_reset(DeviceState *dev) > +{ > + PFlashCFI01 *pfl = PFLASH_CFI01(dev); > + > + pflash_mode_read_array(pfl); > + /* > + * The WSM ready timer occurs at most 150ns after system reset. > + * This model deliberately ignores this delay. > + */ > + pfl->status = 0x80; > +} > + > static Property pflash_cfi01_properties[] = { > DEFINE_PROP_DRIVE("drive", PFlashCFI01, blk), > /* num-blocks is the number of blocks actually visible to the guest, > @@ -901,6 +911,7 @@ static void pflash_cfi01_class_init(ObjectClass *klass, > void *data) > { > DeviceClass *dc = DEVICE_CLASS(klass); > > + dc->reset = pflash_cfi01_system_reset; > dc->realize = pflash_cfi01_realize; > dc->props = pflash_cfi01_properties; > dc->vmsd = &vmstate_pflash; >
