Re: add-acpi-based-floppy-controller-enumeration.patch

[Bjorn Helgaas <bjorn.helgaas-VXdhtT5mjnY@public.gmane.org>]

On Tue, 2005-04-12 at 02:02 -0700, Andrew Morton wrote:
> Bjorn, this has been in -mm for ages.  What did we end up deciding
> to do with it?

You know, I spent a lot of time fiddling with this, but now I'm
not sure there's any real benefit.  We did need the similar work
for i8042, because some ia64 boxes have it, but not others, and
we don't want to blindly poke for it.

But no ia64 boxes have floppy, so there's no reason for us to
even build the driver.

And if somebody *does* want something along these lines, it should
be done via PNPACPI rather than using ACPI directly.  So I think
we should drop this patch.

> From: Bjorn Helgaas <bjorn.helgaas-VXdhtT5mjnY@public.gmane.org>
> 
> This can be disabled with "floppy=no_acpi", which should only be required
> if your BIOS supplies incorrect ACPI _CRS information about I/O ports,
> IRQs, or DMA channels.
> 
> Signed-off-by: Bjorn Helgaas <bjorn.helgaas-VXdhtT5mjnY@public.gmane.org>
> Signed-off-by: Andrew Morton <akpm-3NddpPZAyC0@public.gmane.org>
> ---
> 
>  25-akpm/Documentation/floppy.txt |    6 +
>  25-akpm/drivers/block/floppy.c   |  183 +++++++++++++++++++++++++++++++++++++++
>  2 files changed, 189 insertions(+)
> 
> diff -puN Documentation/floppy.txt~add-acpi-based-floppy-controller-enumeration Documentation/floppy.txt
> --- 25/Documentation/floppy.txt~add-acpi-based-floppy-controller-enumeration	2005-03-11 13:45:42.000000000 -0800
> +++ 25-akpm/Documentation/floppy.txt	2005-03-11 13:45:42.000000000 -0800
> @@ -204,6 +204,12 @@ in /etc/modprobe.conf.
>  	   It's been recommended that take about 1/4 of the default speed
>  	   in some more extreme cases."
>  
> + floppy=no_acpi
> +	Don't enumerate floppy controllers using ACPI namespace.
> +	You may need this if your ACPI is buggy and doesn't report
> +	a floppy controller when it actually exists, or if it
> +	reports incorrect I/O port, IRQ, or DMA information.
> +
>  
>  Supporting utilities and additional documentation:
>  ==================================================
> diff -puN drivers/block/floppy.c~add-acpi-based-floppy-controller-enumeration drivers/block/floppy.c
> --- 25/drivers/block/floppy.c~add-acpi-based-floppy-controller-enumeration	2005-03-11 13:45:42.000000000 -0800
> +++ 25-akpm/drivers/block/floppy.c	2005-03-11 13:48:56.000000000 -0800
> @@ -180,6 +180,13 @@ static int print_unex = 1;
>  #include <linux/device.h>
>  #include <linux/buffer_head.h>	/* for invalidate_buffers() */
>  
> +#ifdef CONFIG_ACPI
> +#include <linux/acpi.h>
> +#include <acpi/acpi_bus.h>
> +
> +static int no_acpi_floppy;
> +#endif
> +
>  /*
>   * PS/2 floppies have much slower step rates than regular floppies.
>   * It's been recommended that take about 1/4 of the default speed
> @@ -4145,6 +4152,9 @@ static struct param_table {
>  	{"slow", NULL, &slow_floppy, 1, 0},
>  	{"unexpected_interrupts", NULL, &print_unex, 1, 0},
>  	{"no_unexpected_interrupts", NULL, &print_unex, 0, 0},
> +#ifdef CONFIG_ACPI
> +	{"no_acpi", NULL, &no_acpi_floppy, 1, 0},
> +#endif
>  	{"L40SX", NULL, &print_unex, 0, 0}
>  
>  	EXTRA_FLOPPY_PARAMS
> @@ -4217,11 +4227,180 @@ static struct kobject *floppy_find(dev_t
>  	return get_disk(disks[drive]);
>  }
>  
> +#ifdef CONFIG_ACPI
> +static int acpi_floppy_registered;
> +static int acpi_floppies;
> +
> +struct region {
> +	unsigned int base;
> +	unsigned int size;
> +};
> +
> +struct floppy_resources {
> +	unsigned int nr_io_regions;
> +	struct region io_region[2];
> +	unsigned int irq;
> +	unsigned int dma_channel;
> +};
> +
> +static acpi_status acpi_floppy_resource(struct acpi_resource *res, void *data)
> +{
> +	struct floppy_resources *fd = (struct floppy_resources *) data;
> +	struct acpi_resource_io *io;
> +	struct acpi_resource_irq *irq;
> +	struct acpi_resource_ext_irq *ext_irq;
> +	struct acpi_resource_dma *dma;
> +	int n;
> +
> +	if (res->id == ACPI_RSTYPE_IO) {
> +		io = &res->data.io;
> +		if (io->range_length) {
> +			n = fd->nr_io_regions;
> +			if (n < 2) {
> +				fd->io_region[n].base = io->min_base_address;
> +				fd->io_region[n].size = io->range_length;
> +				fd->nr_io_regions++;
> +			} else {
> +				printk(KERN_WARNING "%s: ignoring I/O port region 0x%x-0x%x\n",
> +					DEVICE_NAME, io->min_base_address,
> +					io->min_base_address + io->range_length - 1);
> +			}
> +		}
> +	} else if (res->id == ACPI_RSTYPE_IRQ) {
> +		irq = &res->data.irq;
> +		if (irq->number_of_interrupts > 0)
> +			fd->irq = acpi_register_gsi(irq->interrupts[0],
> +				irq->edge_level, irq->active_high_low);
> +	} else if (res->id == ACPI_RSTYPE_EXT_IRQ) {
> +		ext_irq = &res->data.extended_irq;
> +		if (ext_irq->number_of_interrupts > 0)
> +			fd->irq = acpi_register_gsi(ext_irq->interrupts[0],
> +				ext_irq->edge_level, ext_irq->active_high_low);
> +	} else if (res->id == ACPI_RSTYPE_DMA) {
> +		dma = &res->data.dma;
> +		if (dma->number_of_channels > 0)
> +			fd->dma_channel = dma->channels[0];
> +	}
> +	return AE_OK;
> +}
> +
> +static int acpi_floppy_add(struct acpi_device *device)
> +{
> +	struct floppy_resources fd;
> +	acpi_status status;
> +	unsigned int base, dcr;
> +
> +	memset(&fd, 0, sizeof(fd));
> +	status = acpi_walk_resources(device->handle, METHOD_NAME__CRS,
> +		acpi_floppy_resource, &fd);
> +	if (ACPI_FAILURE(status))
> +		return -ENODEV;
> +
> +	strncpy(acpi_device_name(device), "Floppy Controller",
> +		sizeof(acpi_device_name(device)));
> +	printk("ACPI: %s [%s] at I/O 0x%x-0x%x",
> +		acpi_device_name(device), acpi_device_bid(device),
> +		fd.io_region[0].base,
> +		fd.io_region[0].base + fd.io_region[0].size - 1);
> +	if (fd.nr_io_regions > 1) {
> +		if (fd.io_region[1].size == 1)
> +			printk(", 0x%x", fd.io_region[1].base);
> +		else
> +			printk(", 0x%x-0x%x", fd.io_region[1].base,
> +				fd.io_region[1].base + fd.io_region[1].size - 1);
> +	}
> +	printk(" irq %d dma channel %d\n", fd.irq, fd.dma_channel);
> +
> +	/*
> +	 * The most correct resource description is probably of the form
> +	 *    0x3f2-0x3f5, 0x3f7
> +	 * Those are the only ports this driver actually uses.
> +	 *
> +	 * 0x3f0 and 0x3f1 were apparently used on PS/2 systems (though
> +	 * this driver doesn't touch them), and 0x3f6 is used by IDE.
> +	 * Some BIOS's erroneously include those ports, or omit 0x3f7,
> +	 * so we should also be able to handle the following:
> +	 *    0x3f0-0x3f5
> +	 *    0x3f0-0x3f5, 0x3f7
> +	 *    0x3f0-0x3f7
> +	 *    0x3f2-0x3f7
> +	 */
> +	base = fd.io_region[0].base & ~0x7;
> +	dcr = base + 7;
> +
> +#define contains(region, port)	((region).base <= (port) && \
> +				 (port) < (region).base + (region).size)
> +
> +	if (!(contains(fd.io_region[0], dcr) || contains(fd.io_region[1], dcr))) {
> +		printk(KERN_WARNING "ACPI: [%s] doesn't declare FD_DCR; also claiming 0x%x\n",
> +			acpi_device_bid(device), dcr);
> +	}
> +
> +#undef contains
> +
> +	if (acpi_floppies == 0) {
> +		FDC1 = base;
> +		FLOPPY_IRQ = fd.irq;
> +		FLOPPY_DMA = fd.dma_channel;
> +	} else if (acpi_floppies == 1) {
> +		FDC2 = base;
> +		if (fd.irq != FLOPPY_IRQ || fd.dma_channel != FLOPPY_DMA)
> +			printk(KERN_WARNING "%s: different IRQ/DMA info for [%s]; may not work\n",
> +				DEVICE_NAME, acpi_device_bid(device));
> +	} else {
> +		printk(KERN_ERR "%s: only 2 controllers supported; [%s] ignored\n",
> +			DEVICE_NAME, acpi_device_bid(device));
> +		return -ENODEV;
> +	}
> +
> +	acpi_floppies++;
> +	return 0;
> +}
> +
> +static struct acpi_driver acpi_floppy_driver = {
> +	.name	= "floppy",
> +	.ids	= "PNP0700",
> +	.ops	= {
> +		.add	= acpi_floppy_add,
> +	},
> +};
> +
> +static int acpi_floppy_init(void)
> +{
> +	int err;
> +
> +	if (no_acpi_floppy) {
> +		printk("%s: ACPI detection disabled\n", DEVICE_NAME);
> +		return -ENODEV;
> +	}
> +	err = acpi_bus_register_driver(&acpi_floppy_driver);
> +	if (err >= 0)
> +		acpi_floppy_registered = 1;
> +	return err;
> +}
> +
> +static void acpi_floppy_exit(void)
> +{
> +	if (acpi_floppy_registered) {
> +		acpi_bus_unregister_driver(&acpi_floppy_driver);
> +		acpi_floppy_registered = 0;
> +	}
> +}
> +#else
> +static inline int  acpi_floppy_init(void) { return -ENODEV; }
> +static inline void acpi_floppy_exit(void) { }
> +#endif
> +
>  static int __init floppy_init(void)
>  {
>  	int i, unit, drive;
>  	int err, dr;
>  
> +	if (acpi_floppy_init() == 0) {
> +		err = -ENODEV;
> +		goto out_put_acpi;
> +	}
> +
>  	raw_cmd = NULL;
>  
>  	for (dr = 0; dr < N_DRIVE; dr++) {
> @@ -4405,6 +4584,8 @@ out_put_disk:
>  		del_timer(&motor_off_timer[dr]);
>  		put_disk(disks[dr]);
>  	}
> +out_put_acpi:
> +	acpi_floppy_exit();
>  	return err;
>  }
>  
> @@ -4619,6 +4800,8 @@ void cleanup_module(void)
>  	/* eject disk, if any */
>  	fd_eject(0);
>  
> +	acpi_floppy_exit();
> +
>  	wait_for_completion(&device_release);
>  }
>  
> _
> 
> 
> 
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