[PATCH libata-dev-2.6:upstream] implement ata_poll_qc_complete and use it in polling functions
Previously, libata polling functions turned irq back on and completed
qc commands without holding host lock. This creates a race condition
between the polling task and interrupts from other ports on the same
host set or spurious interrupt from itself.
This patch implements ata_poll_qc_complete which enables irq and
completes qc atomically and convert all polling functions.
Note: atapi_packet_task() didn't use to turn irq back on or clear
ATA_FLAG_NOINTR on error exits. This patch makes it use
ata_poll_qc_complete which does both.
Note: With this change, ALL invocations of ata_qc_complete() are now
done under host_set lock.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jgarzik@pobox.com>
Interrupts from devices sharing the same IRQ could cause
ata_host_intr to finish commands being processed by atapi_packet_task
if the commands are using ATA_PROT_ATAPI_NODATA or ATA_PROT_ATAPI_DMA
protocol. This is because libata interrupt handler is unaware that
interrupts are not expected during that period. This patch adds
ATA_FLAG_NOINTR flag to tell the interrupt handler that we're not
expecting interrupts.
Note that once proper HSM is implemented for interrupt-driven PIO,
this should be merged into it and this flag will be removed.
ahci.c is a different kind of beast, so it's left alone.
* The following drivers use ata_qc_issue_prot and ata_interrupt, so
changes in libata core will do.
ata_piix sata_sil sata_svw sata_via sata_sis sata_uli
* The following drivers use ata_qc_issue_prot and custom intr handler.
They need this change to work correctly.
sata_nv sata_vsc
* The following drivers use custom issue function and intr handler.
Currently all custom issue functions don't support ATAPI, so this
change is irrelevant, updated for consistency and to avoid later
mistakes.
sata_promise sata_qstor sata_sx4
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jgarzik@pobox.com>
Description:
After calling the completion callback, the libata error handler might be
running and getting atapi sense data. Clearing the ATA_QCFLAG_ACTIVE flag
at this point might interfere with the libata error handler.
Changes:
- Clear the ATA_QCFLAG_ACTIVE flag before calling the completion callback
(and also before the error handler)
- Add some comment
Signed-off-by: Albert Lee <albertcc@tw.ibm.com>
Signed-off-by: Jeff Garzik <jgarzik@pobox.com>
PATCH 2/2: handle the case when device returns/needs extra data
Description:
Sometimes the device returns/needs extra data than expected.
Changes:
Modify __atapi_pio_bytes() to handle the case where device returns/needs extra data.
- for read case, discard trailing data from the device
- for write case, padding zero data to the device
Signed-off-by: Albert Lee <albertcc@tw.ibm.com>
Signed-off-by: Jeff Garzik <jgarzik@pobox.com>
PATCH 1/2: ata_data_xfer() fix
Changes:
- Modify ata_mmio_data_xfer() and ata_pio_data_xfer() to handle odd-lengthed buffer.
- Add some function comments
This patch does not reuse ap->pad as alignment buffer since
using local variable seems good enough.
Signed-off-by: Albert Lee <albertcc@tw.ibm.com>
Signed-off-by: Jeff Garzik <jgarzik@pobox.com>
This patch lengthens the delay between DET setting and clearing for
COMMRESET from 400us to 1ms. I couldn't find any requiremen regarding
the duration of COMMRESET in SATA I/II specs but AHCI-1.1 10.4.2
states that it should be at least 1ms.
Signed-off-by: Tejun Heo <htejun@gmail.com>
scsi_add_host is the proper place to set the device, but people copy
the scsi_set_device usage from older drivers again and again.
note that this leaves some legacy drivers like qlogicisp/qlogicfc
without pci association in sysfs, but they're scheduled to go away soon
anyway.
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
Problem:
Incorrect md5sum when using ATAPI PIO mode to verify a distro CD.
Root cause: sg traverse problem.
In __atapi_pio_bytes(), if qc->cursg++ is increased and "goto
next_page" is executed, then sg is not updated to the new qc->cursg
and the old sg is overwritten with the new data.
Changes:
- Replace "goto next_page" with "goto next_sg" to make sg updated.
Signed-off-by: Albert Lee <albertcc@tw.ibm.com>
Jens Axboe pointed out that the iounmap() call in libata was occurring
too early, and some drivers (ahci, probably others) were using ioremap'd
memory after it had been unmapped.
The patch should address that problem by way of improving the libata
driver API:
* move ->host_stop() call after all ->port_stop() calls have occurred.
* create default helper function ata_host_stop(), and move iounmap()
call there.
* add ->host_stop_prewalk() hook, use it in sata_qstor.c (hi Mark).
sata_qstor appears to require the host-stop-before-port-stop ordering
that existed prior to applying the attached patch.
When testing ATAPI PIO data transfer on the ppc64 platform, __atapi_pio_bytes() got zero when
sg_dma_len() is used. I checked the <asm-ppc64/scatterlish.h>, the struct scatterlist is defined as:
struct scatterlist {
struct page *page;
unsigned int offset;
unsigned int length;
/* For TCE support */
u32 dma_address;
u32 dma_length;
};
#define sg_dma_address(sg) ((sg)->dma_address)
#define sg_dma_len(sg) ((sg)->dma_length)
So, if the scatterlist is not DMA mapped, sg_dma_len() will return zero on ppc64.
The same problem should occur on the x86-64 platform.
On the i386 platform, sg_dma_len() returns sg->length, that's why the problem does not occur on an i386.
Changes:
- Use sg->length if the scatterlist is not DMA mapped (yet).
Signed-off-by: Albert Lee <albertcc@tw.ibm.com>
Updated patch to fix erroneous flush of COMRESET set and missing flush
of COMRESET clear. Created a new routine scr_write_flush() to try to
prevent this in the future. Also, this patch is based on libata-2.6
instead of the previous libata-dev-2.6 based patch.
Signed-off-by: Brett Russ <russb@emc.com>
Index: libata-2.6/drivers/scsi/libata-core.c
===================================================================
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>
This patch works around an issue with WD drives (and possibly others)
over SiL PATA->SATA Bridges on SATA controllers locking up with
transfers > 200 sectors.
Signed-off-by: Brad Campbell <brad@wasp.net.au>
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
