This happens quite a bit based on Fedora 9 feedback, but already happened in 2.6.24 and possibly earlier. http://www.kerneloops.org/search.php?search=bad_io_access shows the basic backtrace: *bad_io_access ioread8 ata_altstatus ata_std_dev_select ata_dev_select ata_qc_issue_prot ata_qc_issue ata_exec_internal_sg ata_exec_internal ata_dev_read_id ata_eh_recover ata_do_eh ata_bmdma_drive_eh ata_bmdma_error_handler ata_scsi_error scsi_error_handler kthread kernel_thread_helper in all cases, this happens while pata_isapnp is being loaded; so it's not unlikely that this driver stomps on some other driver which then goes splat
Reply-To: akpm@linux-foundation.org On Mon, 19 May 2008 14:46:08 -0700 (PDT) bugme-daemon@bugzilla.kernel.org wrote: > http://bugzilla.kernel.org/show_bug.cgi?id=10752 > > Summary: pata_isapnp driver causes the ata layer to go splat > Product: IO/Storage > Version: 2.5 > KernelVersion: 2.6.25 > Platform: All > OS/Version: Linux > Tree: Mainline > Status: NEW > Severity: normal > Priority: P1 > Component: Serial ATA > AssignedTo: jgarzik@pobox.com > ReportedBy: arjan@linux.intel.com > > > This happens quite a bit based on Fedora 9 feedback, but already happened in > 2.6.24 and possibly earlier. > > http://www.kerneloops.org/search.php?search=bad_io_access > > shows the basic backtrace: > *bad_io_access > ioread8 > ata_altstatus > ata_std_dev_select > ata_dev_select > ata_qc_issue_prot > ata_qc_issue > ata_exec_internal_sg > ata_exec_internal > ata_dev_read_id > ata_eh_recover > ata_do_eh > ata_bmdma_drive_eh > ata_bmdma_error_handler > ata_scsi_error > scsi_error_handler > kthread > kernel_thread_helper > > in all cases, this happens while pata_isapnp is being loaded; so it's not > unlikely that this driver stomps on some other driver which then goes splat > Unclear who maintains pata_isapnp?
On Mon, 19 May 2008 15:25:49 -0700 Andrew Morton <akpm@linux-foundation.org> wrote: > > > > Unclear who maintains pata_isapnp? Alan is on top of this one; he sent a patch to Jeff Garzik already earlier today (will attach to the BZ shortly)
libata-sff: Fix oops reported in kerneloops.org for pnp devices with no ctl From: Alan Cox <alan@redhat.com> --- drivers/ata/libata-sff.c | 23 +++++++++++++++++++++++ include/linux/libata.h | 14 +------------- 2 files changed, 24 insertions(+), 13 deletions(-) diff --git a/drivers/ata/libata-sff.c b/drivers/ata/libata-sff.c index 3c2d228..dbea523 100644 --- a/drivers/ata/libata-sff.c +++ b/drivers/ata/libata-sff.c @@ -256,6 +256,28 @@ u8 ata_sff_altstatus(struct ata_port *ap) } /** + * ata_sff_pause - Flush writes and pause 400 nanoseconds. + * @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) +{ + 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_busy_sleep - sleep until BSY clears, or timeout * @ap: port containing status register to be polled * @tmout_pat: impatience timeout @@ -2723,6 +2745,7 @@ 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/include/linux/libata.h b/include/linux/libata.h index 0f17643..6a94bec 100644 --- a/include/linux/libata.h +++ b/include/linux/libata.h @@ -1437,6 +1437,7 @@ 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); @@ -1498,19 +1499,6 @@ 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