Pavel Hrdina <phrd...@redhat.com> writes: > Hi, > this is the patch to fix incorrect handling of IDE floppy drive controller > emulation > when no media is present. If the guest is booted without a media then the > drive > was not being emulated at all but this patch enables the emulation with no > media present. > > There was a bug in FDC emulation without media. Driver was not able to > recognize that > there is no media in drive. > > This has been tested on both Fedora-16 x86_64 VM and Windows XP VM and the > behaviour > is as expected, i.e. as follows: > > Linux guest (Fedora 16 x86_64) tries "mount /dev/fd0" and exit with error > "mount: /dev/fd0 is not a valid block device" which is the same behavior like > bare metal with real floppy device (you have to load floppy driver at first > using e.g. "modprobe floppy" command). > > For Windows XP guest the Windows floppy driver is trying to seek the virtual > drive > when you want to open it but driver successfully detect that there is no > media in drive > and then it's asking user to insert floppy media in the drive. > > I also tested behavior of this patch if you start guest with "-nodefaults" > and both > Windows and Linux guests detect only FDC but no drive. > > Pavel
As Andreas already pointed out, your commit message needs work. Please limit line length to 70 characters. > This patch has been written with help of specifications from: > http://www.ousob.com/ng/hardware/ngd127.php > http://www.isdaman.com/alsos/hardware/fdc/floppy.htm > http://wiki.osdev.org/Floppy_Disk_Controller > > Signed-off-by: Pavel Hrdina <phrd...@redhat.com> > Signed-off-by: Michal Novotny <minov...@redhat.com> > --- > hw/fdc.c | 14 ++++++++++---- > hw/pc.c | 3 ++- > 2 files changed, 12 insertions(+), 5 deletions(-) > > diff --git a/hw/fdc.c b/hw/fdc.c > index a0236b7..6791eff 100644 > --- a/hw/fdc.c > +++ b/hw/fdc.c > @@ -179,12 +179,14 @@ static void fd_revalidate(FDrive *drv) > FDriveRate rate; > > FLOPPY_DPRINTF("revalidate\n"); > - if (drv->bs != NULL && bdrv_is_inserted(drv->bs)) { > + if (drv->bs != NULL) { > ro = bdrv_is_read_only(drv->bs); > bdrv_get_floppy_geometry_hint(drv->bs, &nb_heads, &max_track, > &last_sect, drv->drive, &drive, &rate); > - if (nb_heads != 0 && max_track != 0 && last_sect != 0) { > - FLOPPY_DPRINTF("User defined disk (%d %d %d)", > + if (!bdrv_is_inserted(drv->bs)) { > + FLOPPY_DPRINTF("No media in drive\n"); > + } else if (nb_heads != 0 && max_track != 0 && last_sect != 0) { > + FLOPPY_DPRINTF("User defined disk (%d %d %d)\n", > nb_heads - 1, max_track, last_sect); > } else { > FLOPPY_DPRINTF("Floppy disk (%d h %d t %d s) %s\n", nb_heads, > @@ -201,11 +203,12 @@ static void fd_revalidate(FDrive *drv) > drv->drive = drive; > drv->media_rate = rate; > } else { > - FLOPPY_DPRINTF("No disk in drive\n"); > + FLOPPY_DPRINTF("Drive disabled\n"); > drv->last_sect = 0; > drv->max_track = 0; > drv->flags &= ~FDISK_DBL_SIDES; > } > + > } > > /********************************************************/ > @@ -937,6 +940,9 @@ static int fdctrl_media_changed(FDrive *drv) > > if (!drv->bs) > return 0; > + /* This is needed for driver to detect there is no media in drive */ > + if (!bdrv_is_inserted(drv->bs)) > + return 1; > if (drv->media_changed) { > drv->media_changed = 0; > ret = 1; > diff --git a/hw/pc.c b/hw/pc.c > index 1f5aacb..29a604b 100644 > --- a/hw/pc.c > +++ b/hw/pc.c > @@ -382,7 +382,8 @@ void pc_cmos_init(ram_addr_t ram_size, ram_addr_t > above_4g_mem_size, > if (floppy) { > fdc_get_bs(fd, floppy); > for (i = 0; i < 2; i++) { > - if (fd[i] && bdrv_is_inserted(fd[i])) { > + /* If there is no media in a drive, we still have the drive > present */ This comment explains why you remove bdrv_is_inserted(). It makes no sense once its gone. > + if (fd[i]) { > bdrv_get_floppy_geometry_hint(fd[i], &nb_heads, &max_track, > &last_sect, FDRIVE_DRV_NONE, > &fd_type[i], &rate); This fixes the CMOS floppy initialization bug I described elsewhere in the thread, because bdrv_get_floppy_geometry_hint() picks FDRIVE_DRV_144 when its bs argument is empty. Are you sure the patches to fdc.c are necessary to fix the bug you're seeing? To be honest, I doubt it.
