floppy: cleanup: do not iterate on current_fdc in do_floppy_init()

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.

Link: https://lore.kernel.org/r/20200410093023.14499-1-w@1wt.eu
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Denis Efremov <efremov@linux.com>

diff --git a/drivers/block/floppy.c b/drivers/block/floppy.c
index 07218f8..8da7921 100644 (file)
--- 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);