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Date: Fri, 13 Feb 2009 09:37:31 -0700
From: Bjorn Helgaas <bjorn.helgaas@...com>
To: Philippe De Muyter <phdm@...qel.be>
Cc: Andrew Morton <akpm@...ux-foundation.org>,
linux-kernel@...r.kernel.org,
Robert Hancock <hancockrwd@...il.com>,
Adam M Belay <abelay@....edu>, Len Brown <lenb@...nel.org>
Subject: Re: [PATCH] floppy: request and release only the ports we actually use
On Friday 13 February 2009 01:55:37 am Philippe De Muyter wrote:
> Andrew,
>
> this is a combined patch replacing the following ones currently in
> the -mm tree :
> floppy-request-only-the-ports-we-actually-use.patch
> floppy-request-only-the-ports-we-actually-use-fix.patch
>
> Bjorn,
>
> Since you did the hard job of collecting the used io-ports and writing
> the changelog and part of this patch, I kept your Signed-off-by :
Great! Thanks for putting this together. This looks like the
right thing to me.
Bjorn
> --
>
> 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: Bjorn Helgaas <bjorn.helgaas@...com>
> Signed-off-by: Philippe De Muyter <phdm@...qel.be>
> Reported-by: Philippe De Muyter <phdm@...qel.be>
> Tested-by: Philippe De Muyter <phdm@...qel.be>
> CC: Adam M Belay <abelay@....edu>
> CC: Robert Hancock <hancockrwd@...il.com>
> ---
> diff -r 94166a3a38bd drivers/block/floppy.c
> --- a/drivers/block/floppy.c Sat Jan 31 15:56:23 2009 -0800
> +++ b/drivers/block/floppy.c Fri Feb 13 09:24:51 2009 +0100
> @@ -558,6 +558,8 @@ static void recalibrate_floppy(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(v
> #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;
> }
>
>
--
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