And this is how a revised one would look. libata-sff: Fix oops reported in kerneloops.org for pnp devices with no ctl From: Alan Cox <alan@xxxxxxxxxx> --- drivers/ata/libata-sff.c | 88 +++++++++++++++++++++++++++++++++++++++------ drivers/ata/pata_icside.c | 2 + include/linux/libata.h | 14 +------ 3 files changed, 78 insertions(+), 26 deletions(-) diff --git a/drivers/ata/libata-sff.c b/drivers/ata/libata-sff.c index 3c2d228..7958da7 100644 --- a/drivers/ata/libata-sff.c +++ b/drivers/ata/libata-sff.c @@ -256,6 +256,73 @@ u8 ata_sff_altstatus(struct ata_port *ap) } /** + * ata_sff_irq_status - Check if the device is busy + * @ap: port where the device is + * + * Determine if the port is currently busy. Uses altstatus + * if available in order to avoid clearing shared IRQ status + * when finding an IRQ source. Non ctl capable devices don't + * share interrupt lines fortunately for us. + * + * LOCKING: + * Inherited from caller. + */ +static u8 ata_sff_irq_status(struct ata_port *ap) +{ + u8 status; + + if (ap->ops->sff_check_altstatus || ap->ioaddr.altstatus_addr) { + status = ata_sff_altstatus(ap); + /* Not us: We are busy */ + if (status & ATA_BUSY) + return status; + } + /* Clear INTRQ latch */ + status = ata_sff_check_status(ap); + return status; +} + +/** + * ata_sff_sync - Flush writes + * @ap: Port to wait for. + * + * CAUTION: + * If we have an mmio device with no ctl and no altstatus + * method this will fail. No such devices are known to exist. + * + * LOCKING: + * Inherited from caller. + */ + +static void ata_sff_sync(struct ata_port *ap) +{ + if (ap->ops->sff_check_altstatus) + ap->ops->sff_check_altstatus(ap); + else if (ap->ioaddr.altstatus_addr) + ioread8(ap->ioaddr.altstatus_addr); + ndelay(400); +} + +/** + * ata_sff_pause - Flush writes and wait 400nS + * @ap: Port to wait for. + * + * CAUTION: + * If we have an mmio device with no ctl and no altstatus + * method this will fail. No such devices are known to exist. + * + * LOCKING: + * Inherited from caller. + */ + +void ata_sff_pause(struct ata_port *ap) +{ + ata_sff_sync(ap); + ndelay(400); +} + + +/** * ata_sff_busy_sleep - sleep until BSY clears, or timeout * @ap: port containing status register to be polled * @tmout_pat: impatience timeout @@ -742,7 +809,7 @@ static void ata_pio_sectors(struct ata_queued_cmd *qc) } else ata_pio_sector(qc); - ata_sff_altstatus(qc->ap); /* flush */ + ata_sff_sync(qc->ap); /* flush */ } /** @@ -763,7 +830,7 @@ static void atapi_send_cdb(struct ata_port *ap, struct ata_queued_cmd *qc) WARN_ON(qc->dev->cdb_len < 12); ap->ops->sff_data_xfer(qc->dev, qc->cdb, qc->dev->cdb_len, 1); - ata_sff_altstatus(ap); /* flush */ + ata_sff_pause(ap); switch (qc->tf.protocol) { case ATAPI_PROT_PIO: @@ -905,7 +972,7 @@ static void atapi_pio_bytes(struct ata_queued_cmd *qc) if (unlikely(__atapi_pio_bytes(qc, bytes))) goto err_out; - ata_sff_altstatus(ap); /* flush */ + ata_sff_pause(ap); /* flush */ return; @@ -1489,14 +1556,10 @@ inline unsigned int ata_sff_host_intr(struct ata_port *ap, goto idle_irq; } - /* check altstatus */ - status = ata_sff_altstatus(ap); - if (status & ATA_BUSY) - goto idle_irq; - /* check main status, clearing INTRQ */ - status = ap->ops->sff_check_status(ap); - if (unlikely(status & ATA_BUSY)) + /* check main status, clearing INTRQ if needed */ + status = ata_sff_irq_status(ap); + if (status & ATA_BUSY) goto idle_irq; /* ack bmdma irq events */ @@ -2030,7 +2093,7 @@ void ata_sff_error_handler(struct ata_port *ap) ap->ops->bmdma_stop(qc); } - ata_sff_altstatus(ap); + ata_sff_sync(ap); /* FIXME: We don't need this */ ap->ops->sff_check_status(ap); ap->ops->sff_irq_clear(ap); @@ -2203,7 +2266,7 @@ void ata_bmdma_stop(struct ata_queued_cmd *qc) mmio + ATA_DMA_CMD); /* one-PIO-cycle guaranteed wait, per spec, for HDMA1:0 transition */ - ata_sff_altstatus(ap); /* dummy read */ + ata_sff_sync(ap); /* dummy read */ } /** @@ -2723,6 +2786,7 @@ EXPORT_SYMBOL_GPL(ata_sff_dumb_qc_prep); EXPORT_SYMBOL_GPL(ata_sff_dev_select); EXPORT_SYMBOL_GPL(ata_sff_check_status); EXPORT_SYMBOL_GPL(ata_sff_altstatus); +EXPORT_SYMBOL_GPL(ata_sff_pause); EXPORT_SYMBOL_GPL(ata_sff_busy_sleep); EXPORT_SYMBOL_GPL(ata_sff_wait_ready); EXPORT_SYMBOL_GPL(ata_sff_tf_load); diff --git a/drivers/ata/pata_icside.c b/drivers/ata/pata_icside.c index 1713843..bc685cd 100644 --- a/drivers/ata/pata_icside.c +++ b/drivers/ata/pata_icside.c @@ -269,7 +269,7 @@ static void pata_icside_bmdma_stop(struct ata_queued_cmd *qc) disable_dma(state->dma); - /* see ata_bmdma_stop */ + /* see ata_bmdma_stop: we know we have a ctl port in this case */ ata_sff_altstatus(ap); } diff --git a/include/linux/libata.h b/include/linux/libata.h index 4a92fba..8eb5022 100644 --- a/include/linux/libata.h +++ b/include/linux/libata.h @@ -1435,6 +1435,7 @@ extern void ata_sff_qc_prep(struct ata_queued_cmd *qc); extern void ata_sff_dumb_qc_prep(struct ata_queued_cmd *qc); extern void ata_sff_dev_select(struct ata_port *ap, unsigned int device); extern u8 ata_sff_check_status(struct ata_port *ap); +extern void ata_sff_pause(struct ata_port *ap); extern u8 ata_sff_altstatus(struct ata_port *ap); extern int ata_sff_busy_sleep(struct ata_port *ap, unsigned long timeout_pat, unsigned long timeout); @@ -1496,19 +1497,6 @@ extern int ata_pci_sff_init_one(struct pci_dev *pdev, #endif /* CONFIG_PCI */ /** - * ata_sff_pause - Flush writes and pause 400 nanoseconds. - * @ap: Port to wait for. - * - * LOCKING: - * Inherited from caller. - */ -static inline void ata_sff_pause(struct ata_port *ap) -{ - ata_sff_altstatus(ap); - ndelay(400); -} - -/** * ata_sff_busy_wait - Wait for a port status register * @ap: Port to wait for. * @bits: bits that must be clear -- To unsubscribe from this list: send the line "unsubscribe linux-ide" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html