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Commit 5a74db06 authored by Philippe De Muyter's avatar Philippe De Muyter Committed by Linus Torvalds
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floppy: request and release only the ports we actually use 

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 and release only the ports it
actually uses.  It also factors out the request/release stuff and the
io-ports list so they're all in one place now.

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: default avatarBjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: default avatarPhilippe De Muyter <phdm@macqel.be>
Reported-by: default avatarPhilippe De Muyter <phdm@macqel.be>
Tested-by: default avatarPhilippe De Muyter <phdm@macqel.be>
Cc: Adam M Belay <abelay@mit.edu>
Cc: Robert Hancock <hancockrwd@gmail.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent ffa7525c

drivers/block/floppy.c

+52 −27
Original line number Diff line number Diff line
@@ -558,6 +558,8 @@ static void process_fd_request(void); 
static void recalibrate_floppy(void);

static void floppy_shutdown(unsigned long);



static int floppy_request_regions(int);

static void floppy_release_regions(int);

static int floppy_grab_irq_and_dma(void);

static void floppy_release_irq_and_dma(void);
@@ -4274,8 +4276,7 @@ static int __init floppy_init(void) 
		FDCS->rawcmd = 2;

		if (user_reset_fdc(-1, FD_RESET_ALWAYS, 0)) {

			/* free ioports reserved by floppy_grab_irq_and_dma() */

			release_region(FDCS->address + 2, 4);

			release_region(FDCS->address + 7, 1);

			floppy_release_regions(fdc);

			FDCS->address = -1;

			FDCS->version = FDC_NONE;

			continue;
@@ -4284,8 +4285,7 @@ static int __init floppy_init(void) 
		FDCS->version = get_fdc_version();

		if (FDCS->version == FDC_NONE) {

			/* free ioports reserved by floppy_grab_irq_and_dma() */

			release_region(FDCS->address + 2, 4);

			release_region(FDCS->address + 7, 1);

			floppy_release_regions(fdc);

			FDCS->address = -1;

			continue;

		}
@@ -4358,6 +4358,47 @@ out_put_disk: 


static DEFINE_SPINLOCK(floppy_usage_lock);



static const struct io_region {

	int offset;

	int size;

} io_regions[] = {

	{ 2, 1 },

	/* address + 3 is sometimes reserved by pnp bios for motherboard */

	{ 4, 2 },

	/* address + 6 is reserved, and may be taken by IDE.

	 * Unfortunately, Adaptec doesn't know this :-(, */

	{ 7, 1 },

};



static void floppy_release_allocated_regions(int fdc, const struct io_region *p)

{

	while (p != io_regions) {

		p--;

		release_region(FDCS->address + p->offset, p->size);

	}

}



#define ARRAY_END(X) (&((X)[ARRAY_SIZE(X)]))



static int floppy_request_regions(int fdc)

{

	const struct io_region *p;



	for (p = io_regions; p < ARRAY_END(io_regions); p++) {

		if (!request_region(FDCS->address + p->offset, p->size, "floppy")) {

			DPRINT("Floppy io-port 0x%04lx in use\n", FDCS->address + p->offset);

			floppy_release_allocated_regions(fdc, p);

			return -EBUSY;

		}

	}

	return 0;

}



static void floppy_release_regions(int fdc)

{

	floppy_release_allocated_regions(fdc, ARRAY_END(io_regions));

}



static int floppy_grab_irq_and_dma(void)

{

	unsigned long flags;
@@ -4399,18 +4440,8 @@ 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")) {

				DPRINT("Floppy io-port 0x%04lx in use\n",

				       FDCS->address + 2);

				goto cleanup1;

			}

			if (!request_region(FDCS->address + 7, 1, "floppy DIR")) {

				DPRINT("Floppy io-port 0x%04lx in use\n",

				       FDCS->address + 7);

				goto cleanup2;

			}

			/* address + 6 is reserved, and may be taken by IDE.

			 * Unfortunately, Adaptec doesn't know this :-(, */

			if (floppy_request_regions(fdc))

				goto cleanup;

		}

	}

	for (fdc = 0; fdc < N_FDC; fdc++) {
@@ -4432,15 +4463,11 @@ static int floppy_grab_irq_and_dma(void) 
	fdc = 0;

	irqdma_allocated = 1;

	return 0;

cleanup2:

	release_region(FDCS->address + 2, 4);

cleanup1:

cleanup:

	fd_free_irq();

	fd_free_dma();

	while (--fdc >= 0) {

		release_region(FDCS->address + 2, 4);

		release_region(FDCS->address + 7, 1);

	}

	while (--fdc >= 0)

		floppy_release_regions(fdc);

	spin_lock_irqsave(&floppy_usage_lock, flags);

	usage_count--;

	spin_unlock_irqrestore(&floppy_usage_lock, flags);
@@ -4501,10 +4528,8 @@ static void floppy_release_irq_and_dma(void) 
#endif

	old_fdc = fdc;

	for (fdc = 0; fdc < N_FDC; fdc++)

		if (FDCS->address != -1) {

			release_region(FDCS->address + 2, 4);

			release_region(FDCS->address + 7, 1);

		}

		if (FDCS->address != -1)

			floppy_release_regions(fdc);

	fdc = old_fdc;

}