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Subject[PATCH] ACPI-based floppy controller enumeration
Date
Add ACPI-based floppy controller enumeration.  This fixes
one problem exposed when I removed the unconditional ACPI
PCI IRQ routing.

ACPI-based enumeration can be disabled with "floppy=no_acpi".
That 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@hp.com>

===== Documentation/floppy.txt 1.1 vs edited =====
--- 1.1/Documentation/floppy.txt 2002-02-05 10:40:38 -07:00
+++ edited/Documentation/floppy.txt 2004-08-18 15:41:37 -06:00
@@ -187,6 +187,11 @@
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 reports incorrect
+ I/O port, IRQ, or DMA information.
+


Supporting utilities and additional documentation:
===== drivers/block/floppy.c 1.103 vs edited =====
--- 1.103/drivers/block/floppy.c 2004-08-02 02:00:45 -06:00
+++ edited/drivers/block/floppy.c 2004-08-18 15:54:41 -06:00
@@ -181,6 +181,13 @@
#include <linux/device.h>
#include <linux/buffer_head.h> /* for invalidate_buffers() */

+#ifdef CONFIG_ACPI_BUS
+#include <linux/acpi.h>
+#include <acpi/acpi_bus.h>
+
+static int no_acpi;
+#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
@@ -4150,6 +4157,9 @@
{"slow", NULL, &slow_floppy, 1, 0},
{"unexpected_interrupts", NULL, &print_unex, 1, 0},
{"no_unexpected_interrupts", NULL, &print_unex, 0, 0},
+#ifdef CONFIG_ACPI_BUS
+ {"no_acpi", NULL, &no_acpi, 1, 0},
+#endif
{"L40SX", NULL, &print_unex, 0, 0}

EXTRA_FLOPPY_PARAMS
@@ -4222,10 +4232,123 @@
return get_disk(disks[drive]);
}

+#ifdef CONFIG_ACPI_BUS
+static int acpi_floppies;
+
+struct floppy_resources {
+ unsigned int port;
+ unsigned int nr_ports;
+ unsigned int irq;
+ unsigned int dma_channel;
+};
+
+static acpi_status acpi_floppy_resource(struct acpi_resource *res, void *data)
+{
+ struct floppy_resources *floppy = (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;
+
+ if (res->id == ACPI_RSTYPE_IO) {
+ io = &res->data.io;
+ if (io->range_length) {
+ floppy->port = io->min_base_address;
+ floppy->nr_ports = io->range_length;
+ }
+ } else if (res->id == ACPI_RSTYPE_IRQ) {
+ irq = &res->data.irq;
+ if (irq->number_of_interrupts > 0)
+ floppy->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)
+ floppy->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)
+ floppy->dma_channel = dma->channels[0];
+ }
+ return AE_OK;
+}
+
+static int acpi_floppy_add(struct acpi_device *device)
+{
+ struct floppy_resources floppy;
+ acpi_status status;
+
+ memset(&floppy, 0, sizeof(floppy));
+ status = acpi_walk_resources(device->handle, METHOD_NAME__CRS,
+ acpi_floppy_resource, &floppy);
+ if (ACPI_FAILURE(status))
+ return -ENODEV;
+
+ printk("%s: controller ACPI %s at I/O 0x%x-0x%x irq %d dma channel %d\n",
+ DEVICE_NAME, device->pnp.bus_id,
+ floppy.port, floppy.port + floppy.nr_ports - 1,
+ floppy.irq, floppy.dma_channel);
+
+ /*
+ * The driver assumes I/O port regions like 0x3f0-0x3f5, but it
+ * ignores the first two ports (i.e., 0x3f0 and 0x3f1), which are
+ * for PS/2 systems. Since no PS/2 systems have ACPI, we should
+ * get a region like 0x3f2-0x3f5, so we adjust it down to what the
+ * driver expects.
+ */
+ acpi_floppies++;
+ if (acpi_floppies == 1) {
+ FDC1 = floppy.port - 2;
+ FLOPPY_IRQ = floppy.irq;
+ FLOPPY_DMA = floppy.dma_channel;
+ } else if (acpi_floppies == 2) {
+ FDC2 = floppy.port - 2;
+ if (floppy.irq != FLOPPY_IRQ || floppy.dma_channel != FLOPPY_DMA)
+ printk(KERN_WARNING "%s: different IRQ/DMA info for %s; may not work\n",
+ DEVICE_NAME, device->pnp.bus_id);
+ } else {
+ printk(KERN_ERR "%s: only 2 controllers supported; %s ignored\n",
+ DEVICE_NAME, device->pnp.bus_id);
+ return -ENODEV;
+ }
+
+ return 0;
+}
+
+static int acpi_floppy_remove(struct acpi_device *device, int type)
+{
+ printk(KERN_ERR "%s: remove ACPI %s not supported\n", DEVICE_NAME,
+ device->pnp.bus_id);
+ return -EINVAL;
+}
+
+static struct acpi_driver acpi_floppy_driver = {
+ .name = "floppy",
+ .ids = "PNP0700",
+ .ops = {
+ .add = acpi_floppy_add,
+ .remove = acpi_floppy_remove,
+ },
+};
+
+static int acpi_floppy_init(void)
+{
+ if (no_acpi)
+ return -ENODEV;
+ return acpi_bus_register_driver(&acpi_floppy_driver);
+}
+#endif
+
int __init floppy_init(void)
{
int i, unit, drive;
int err, dr;
+
+#ifdef CONFIG_ACPI_BUS
+ if (acpi_floppy_init() == 0)
+ return -ENODEV;
+#endif

raw_cmd = NULL;

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