[PATCH 24/23] floppy: cleanup: do not iterate on current_fdc in do_floppy_init()

Willy Tarreau
2020-04-10T09:30:36Z

There's no need to iterate on current_fdc in do_floppy_init() anymore,
in the first case it's only used as an array index to access fdc_state[],
so let's get rid of this confusing assignment. The second case is a bit
trickier because user_reset_fdc() needs to already know current_fdc when
called with drive==-1 due to this call chain:

user_reset_fdc()
lock_fdc()
set_fdc()
drive<0 ==> new_fdc = current_fdc

Note that current_drive is not used in this code part and may even not
match a unit belonging to current_fdc. Instead of passing -1 we can
simply pass the first drive of the FDC being initialized, which is even
cleaner as it will allow the function chain above to consistently assign
both variables.

Signed-off-by: Willy Tarreau <w@1wt.eu>
---
drivers/block/floppy.c | 38 ++++++++++++++++++--------------------
1 file changed, 18 insertions(+), 20 deletions(-)

diff --git a/drivers/block/floppy.c b/drivers/block/floppy.c
index 07218f8b17f9..8da7921659f1 100644
--- a/drivers/block/floppy.c
+++ b/drivers/block/floppy.c
@@ -4657,16 +4657,15 @@ static int __init do_floppy_init(void)
config_types();

for (i = 0; i < N_FDC; i++) {
- current_fdc = i;
- memset(&fdc_state[current_fdc], 0, sizeof(*fdc_state));
- fdc_state[current_fdc].dtr = -1;
- fdc_state[current_fdc].dor = 0x4;
+ memset(&fdc_state[i], 0, sizeof(*fdc_state));
+ fdc_state[i].dtr = -1;
+ fdc_state[i].dor = 0x4;
#if defined(__sparc__) || defined(__mc68000__)
/*sparcs/sun3x don't have a DOR reset which we can fall back on to */
#ifdef __mc68000__
if (MACH_IS_SUN3X)
#endif
- fdc_state[current_fdc].version = FDC_82072A;
+ fdc_state[i].version = FDC_82072A;
#endif
}

@@ -4708,30 +4707,29 @@ static int __init do_floppy_init(void)
msleep(10);

for (i = 0; i < N_FDC; i++) {
- current_fdc = i;
- fdc_state[current_fdc].driver_version = FD_DRIVER_VERSION;
+ fdc_state[i].driver_version = FD_DRIVER_VERSION;
for (unit = 0; unit < 4; unit++)
- fdc_state[current_fdc].track[unit] = 0;
- if (fdc_state[current_fdc].address == -1)
+ fdc_state[i].track[unit] = 0;
+ if (fdc_state[i].address == -1)
continue;
- fdc_state[current_fdc].rawcmd = 2;
- if (user_reset_fdc(-1, FD_RESET_ALWAYS, false)) {
+ fdc_state[i].rawcmd = 2;
+ if (user_reset_fdc(REVDRIVE(i, 0), FD_RESET_ALWAYS, false)) {
/* free ioports reserved by floppy_grab_irq_and_dma() */
- floppy_release_regions(current_fdc);
- fdc_state[current_fdc].address = -1;
- fdc_state[current_fdc].version = FDC_NONE;
+ floppy_release_regions(i);
+ fdc_state[i].address = -1;
+ fdc_state[i].version = FDC_NONE;
continue;
}
/* Try to determine the floppy controller type */
- fdc_state[current_fdc].version = get_fdc_version(current_fdc);
- if (fdc_state[current_fdc].version == FDC_NONE) {
+ fdc_state[i].version = get_fdc_version(i);
+ if (fdc_state[i].version == FDC_NONE) {
/* free ioports reserved by floppy_grab_irq_and_dma() */
- floppy_release_regions(current_fdc);
- fdc_state[current_fdc].address = -1;
+ floppy_release_regions(i);
+ fdc_state[i].address = -1;
continue;
}
if (can_use_virtual_dma == 2 &&
- fdc_state[current_fdc].version < FDC_82072A)
+ fdc_state[i].version < FDC_82072A)
can_use_virtual_dma = 0;

have_no_fdc = 0;
@@ -4739,7 +4737,7 @@ static int __init do_floppy_init(void)
* properly, so force a reset for the standard FDC clones,
* to avoid interrupt garbage.
*/
- user_reset_fdc(-1, FD_RESET_ALWAYS, false);
+ user_reset_fdc(REVDRIVE(i, 0), FD_RESET_ALWAYS, false);
}
current_fdc = 0;
cancel_delayed_work(&fd_timeout);
--
2.20.1