Re: [Qemu-devel] [PATCH v2] fdc: fix media change detection for windows

[Pavel Hrdina]

On 06/05/2012 05:56 PM, Kevin Wolf wrote:
> Am 05.06.2012 17:50, schrieb Pavel Hrdina:
> > Sorry, I forget the qtest. I'll create it and send it again.
> >
> > Pavel
> >
> > On 06/05/2012 05:46 PM, Pavel Hrdina wrote:
> > > The Windows uses 'READ' command at the start of an instalation
> > > without checking the 'dir' register. We have to abort the transfer
> > > with an abnormal termination if there is no media in the drive.
> > >
> > > We have to also check the 'media_change' bit in the 'fd_seek'. This
> > > internal seek clears the 'media_change' bit, too, if there is
> > > a media inserted.
> > >
> > > Signed-off-by: Pavel Hrdina<address@hidden>
> > > ---
> > >    hw/fdc.c |    7 ++++++-
> > >    1 files changed, 6 insertions(+), 1 deletions(-)
> > >
> > > diff --git a/hw/fdc.c b/hw/fdc.c
> > > index 30d34e3..2d6dd30 100644
> > > --- a/hw/fdc.c
> > > +++ b/hw/fdc.c
> > > @@ -127,8 +127,13 @@ static int fd_seek(FDrive *drv, uint8_t head, uint8_t 
> > > track, uint8_t sect,
> > >        uint32_t sector;
> > >        int ret;
> > >
> > > +    if (drv->bs != NULL&&   bdrv_is_inserted(drv->bs)) {
> > > +        drv->media_changed = 0;
> > > +    }
> > > +
> > >        if (track>   drv->max_track ||
> > > -        (head != 0&&   (drv->flags&   FDISK_DBL_SIDES) == 0)) {
> > > +        (head != 0&&   (drv->flags&   FDISK_DBL_SIDES) == 0) ||
> > > +        drv->media_changed) {
> Why not directly use bdrv_is_inserted() here?
>
> Fiddling around with media_changed feels rather hacky and is strictly
> speaking incorrect because a step pulse is not guaranteed to happen in
> the following code. The floppy code doesn't get it quite right today
> anyway, but a hack like this would contribute to the problem.
>
>
> > >            FLOPPY_DPRINTF("try to read %d %02x %02x (max=%d %d %02x %02x)\n",
> > >                           head, track, sect, 1,
> > >                           (drv->flags&   FDISK_DBL_SIDES) == 0 ? 0 : 1,
> Kevin
I'll move the code into the end of 'fd_seek' function, where a step is 
guaranteed. Internal seek should also reset the 'media_changed' bit if 
there is a media in the drive. I'll create the qtest tomorrow then I'll 
send another version of this patch.

Pavel