From 21b1ed74ee3667dcabcba92e486988ea9119a085 Mon Sep 17 00:00:00 2001 From: Albert Lee <albertcc@tw.ibm.com> Date: Fri, 29 Apr 2005 17:34:59 +0800 Subject: [PATCH] libata: Prevent the interrupt handler from completing a command twice Problem: During the libata CD-ROM stress test, sometimes the "BUG: timeout without command" error is seen. Root cause: Unexpected interrupt occurs after the ata_qc_complete() is called, but before the SCSI error handler. The interrupt handler is invoked before the SCSI error handler, and it clears the command by calling ata_qc_complete() again. Later when the SCSI error handler is run, the ata_queued_cmd is already gone, causing the "BUG: timeout without command" error. Changes: - Use the ATA_QCFLAG_ACTIVE flag to prevent the interrupt handler from completing the command twice, before the scsi_error_handler. Signed-off-by: Albert Lee <albertcc@tw.ibm.com> --- drivers/scsi/libata-core.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/drivers/scsi/libata-core.c b/drivers/scsi/libata-core.c index 0b5d3a5b7e..f70935cba1 100644 --- a/drivers/scsi/libata-core.c +++ b/drivers/scsi/libata-core.c @@ -2539,7 +2539,7 @@ static void atapi_request_sense(struct ata_port *ap, struct ata_device *dev, ata_sg_init_one(qc, cmd->sense_buffer, sizeof(cmd->sense_buffer)); qc->dma_dir = DMA_FROM_DEVICE; - memset(&qc->cdb, 0, sizeof(ap->cdb_len)); + memset(&qc->cdb, 0, ap->cdb_len); qc->cdb[0] = REQUEST_SENSE; qc->cdb[4] = SCSI_SENSE_BUFFERSIZE; @@ -2811,6 +2811,7 @@ void ata_qc_complete(struct ata_queued_cmd *qc, u8 drv_stat) /* call completion callback */ rc = qc->complete_fn(qc, drv_stat); + qc->flags &= ~ATA_QCFLAG_ACTIVE; /* if callback indicates not to complete command (non-zero), * return immediately @@ -3229,7 +3230,8 @@ irqreturn_t ata_interrupt (int irq, void *dev_instance, struct pt_regs *regs) struct ata_queued_cmd *qc; qc = ata_qc_from_tag(ap, ap->active_tag); - if (qc && (!(qc->tf.ctl & ATA_NIEN))) + if (qc && (!(qc->tf.ctl & ATA_NIEN)) && + (qc->flags & ATA_QCFLAG_ACTIVE)) handled |= ata_host_intr(ap, qc); } } -- cgit v1.2.2