From ee2f344b33b507af23610c8fdfdde38d7c10fb33 Mon Sep 17 00:00:00 2001 From: Alan Cox Date: Sun, 10 Dec 2006 02:20:39 -0800 Subject: [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 (Most of the hard work done by Stratus however) Cc: Jens Axboe Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/ide/ide-cd.c | 7 +++++++ drivers/ide/pci/piix.c | 4 ++++ include/linux/ide.h | 1 + 3 files changed, 12 insertions(+) diff --git a/drivers/ide/ide-cd.c b/drivers/ide/ide-cd.c index 88214943d00..5969cec58dc 100644 --- a/drivers/ide/ide-cd.c +++ b/drivers/ide/ide-cd.c @@ -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) diff --git a/drivers/ide/pci/piix.c b/drivers/ide/pci/piix.c index cdc3aab9ebc..b1e9a8eba6b 100644 --- a/drivers/ide/pci/piix.c +++ b/drivers/ide/pci/piix.c @@ -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; diff --git a/include/linux/ide.h b/include/linux/ide.h index 9c2050293f1..64e070f62a8 100644 --- a/include/linux/ide.h +++ b/include/linux/ide.h @@ -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() */ -- cgit v1.2.3