Messages in this thread Patch in this message | | | From | Bjorn Helgaas <> | Subject | [PATCH] floppy: request only the ports we actually use | Date | Thu, 05 Feb 2009 10:48:59 -0700 |
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The floppy driver requests an I/O port it doesn't need, and sometimes this causes a conflict with a motherboard device reported by PNPBIOS.
This patch makes the floppy driver request only the ports it actually uses.
The current floppy driver uses only these ports: 0x3f2 (FD_DOR) 0x3f4 (FD_STATUS) 0x3f5 (FD_DATA) 0x3f7 (FD_DCR/FD_DIR) but it requests 0x3f2-0x3f5 and 0x3f7, which includes the unused port 0x3f3.
Some BIOSes report 0x3f3 as a motherboard resource. The PNP system driver reserves that, which causes a conflict when the floppy driver requests 0x3f2-0x3f5 later.
Philippe reported that this conflict broke the floppy driver between 2.6.11 and 2.6.22. His PNPBIOS reports these devices:
$ cat 00:07/id 00:07/resources # motherboard device PNP0c02 state = active io 0x80-0x80 io 0x10-0x1f io 0x22-0x3f io 0x44-0x5f io 0x90-0x9f io 0xa2-0xbf io 0x3f0-0x3f1 io 0x3f3-0x3f3
$ cat 00:03/id 00:03/resources # floppy device PNP0700 state = active io 0x3f4-0x3f5 io 0x3f2-0x3f2
Reference: http://lkml.org/lkml/2009/1/31/162
Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com> Reported-by: Philippe De Muyter <phdm@macqel.be> Tested-by: Philippe De Muyter <phdm@macqel.be> CC: Adam M Belay <abelay@mit.edu> CC: Robert Hancock <hancockrwd@gmail.com> --- drivers/block/floppy.c | 16 ++++++++++++---- 1 files changed, 12 insertions(+), 4 deletions(-)
diff --git a/drivers/block/floppy.c b/drivers/block/floppy.c index cf29cc4..44f711b 100644 --- a/drivers/block/floppy.c +++ b/drivers/block/floppy.c @@ -4399,15 +4399,20 @@ static int floppy_grab_irq_and_dma(void) for (fdc = 0; fdc < N_FDC; fdc++) { if (FDCS->address != -1) { - if (!request_region(FDCS->address + 2, 4, "floppy")) { + if (!request_region(FDCS->address + 2, 1, "floppy")) { DPRINT("Floppy io-port 0x%04lx in use\n", FDCS->address + 2); goto cleanup1; } + if (!request_region(FDCS->address + 4, 2, "floppy")) { + DPRINT("Floppy io-port 0x%04lx in use\n", + FDCS->address + 4); + goto cleanup2; + } if (!request_region(FDCS->address + 7, 1, "floppy DIR")) { DPRINT("Floppy io-port 0x%04lx in use\n", FDCS->address + 7); - goto cleanup2; + goto cleanup3; } /* address + 6 is reserved, and may be taken by IDE. * Unfortunately, Adaptec doesn't know this :-(, */ @@ -4432,13 +4437,16 @@ static int floppy_grab_irq_and_dma(void) fdc = 0; irqdma_allocated = 1; return 0; +cleanup3: + release_region(FDCS->address + 4, 2); cleanup2: - release_region(FDCS->address + 2, 4); + release_region(FDCS->address + 2, 1); cleanup1: fd_free_irq(); fd_free_dma(); while (--fdc >= 0) { - release_region(FDCS->address + 2, 4); + release_region(FDCS->address + 2, 1); + release_region(FDCS->address + 4, 2); release_region(FDCS->address + 7, 1); } spin_lock_irqsave(&floppy_usage_lock, flags);
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