diff options
| author | Jan Beulich <jbeulich@novell.com> | 2007-10-16 23:27:32 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2007-10-17 08:42:55 -0700 |
| commit | 2e9c47cd4d451c57868c898672802eec9867ae1e (patch) | |
| tree | ac2d7169107c579086bcaa8731ca3d9812776e59 | |
| parent | e98c3202916d30f0e6f59735801baa69bc3348ac (diff) | |
| download | linux-2e9c47cd4d451c57868c898672802eec9867ae1e.tar.gz linux-2e9c47cd4d451c57868c898672802eec9867ae1e.tar.bz2 linux-2e9c47cd4d451c57868c898672802eec9867ae1e.zip | |
floppy: tolerate DMA channel unavailability
The floppy driver is already written to be able to operate in virtual DMA
mode. Thus it can easily be adjusted to tolerate failure from
fd_request_dma() as long as virtual DMA mode is not disallowed.
Signed-off-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | drivers/block/floppy.c | 14 |
1 files changed, 9 insertions, 5 deletions
diff --git a/drivers/block/floppy.c b/drivers/block/floppy.c index 80483aac4cc9..72803a3585ff 100644 --- a/drivers/block/floppy.c +++ b/drivers/block/floppy.c @@ -4388,11 +4388,15 @@ static int floppy_grab_irq_and_dma(void) if (fd_request_dma()) { DPRINT("Unable to grab DMA%d for the floppy driver\n", FLOPPY_DMA); - fd_free_irq(); - spin_lock_irqsave(&floppy_usage_lock, flags); - usage_count--; - spin_unlock_irqrestore(&floppy_usage_lock, flags); - return -1; + if (can_use_virtual_dma & 2) + use_virtual_dma = can_use_virtual_dma = 1; + if (!(can_use_virtual_dma & 1)) { + fd_free_irq(); + spin_lock_irqsave(&floppy_usage_lock, flags); + usage_count--; + spin_unlock_irqrestore(&floppy_usage_lock, flags); + return -1; + } } for (fdc = 0; fdc < N_FDC; fdc++) { |