[PATCH] ide-cd: Handle strange interrupt on the Intel ESB2

The ESB2 appears to emit spurious DMA interrupts when configured for native
mode and handling ATAPI devices.  Stratus were able to pin this bug down and
produce a patch.  This is a rework which applies the fixup only to the ESB2
(for now).  We can apply it to other chips later if the same problem is found.

This code has been tested and confirmed to fix the problem on the tested
systems.

Signed-off-by: Alan Cox <alan@redhat.com>
(Most of the hard work done by Stratus however)
Cc: Jens Axboe <axboe@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This commit is contained in:
Alan Cox 2006-12-10 02:20:39 -08:00 committed by Linus Torvalds
parent 33859f7f97
commit ee2f344b33
3 changed files with 12 additions and 0 deletions

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@ -687,8 +687,15 @@ static void ide_dump_status_no_sense(ide_drive_t *drive, const char *msg, u8 sta
static int cdrom_decode_status(ide_drive_t *drive, int good_stat, int *stat_ret)
{
struct request *rq = HWGROUP(drive)->rq;
ide_hwif_t *hwif = HWIF(drive);
int stat, err, sense_key;
/* We may have bogus DMA interrupts in PIO state here */
if (HWIF(drive)->dma_status && hwif->atapi_irq_bogon) {
stat = hwif->INB(hwif->dma_status);
/* Should we force the bit as well ? */
hwif->OUTB(stat, hwif->dma_status);
}
/* Check for errors. */
stat = HWIF(drive)->INB(IDE_STATUS_REG);
if (stat_ret)

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@ -505,6 +505,10 @@ static void __devinit init_hwif_piix(ide_hwif_t *hwif)
/* This is a painful system best to let it self tune for now */
return;
}
/* ESB2 appears to generate spurious DMA interrupts in PIO mode
when in native mode */
if (hwif->pci_dev->device == PCI_DEVICE_ID_INTEL_ESB2_18)
hwif->atapi_irq_bogon = 1;
hwif->autodma = 0;
hwif->tuneproc = &piix_tune_drive;

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@ -796,6 +796,7 @@ typedef struct hwif_s {
unsigned sg_mapped : 1; /* sg_table and sg_nents are ready */
unsigned no_io_32bit : 1; /* 1 = can not do 32-bit IO ops */
unsigned err_stops_fifo : 1; /* 1=data FIFO is cleared by an error */
unsigned atapi_irq_bogon : 1; /* Generates spurious DMA interrupts in PIO mode */
struct device gendev;
struct completion gendev_rel_comp; /* To deal with device release() */