The patch titled
libata: limit post SRST nsect/lbal wait to ~100ms
has been added to the -mm tree. Its filename is
libata-limit-post-srst-nsect-lbal-wait-to-100ms.patch
*** Remember to use Documentation/SubmitChecklist when testing your code ***
See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this
------------------------------------------------------
Subject: libata: limit post SRST nsect/lbal wait to ~100ms
From: Tejun Heo <htejun@xxxxxxxxx>
After SRST, libata used to wait for nsect/lbal to be set to 1/1 for the
slave device. However, some ATAPI devices don't set nsect/lbal after SRST
and the wait itself isn't too useful as we're gonna wait for !BSY right
after that anyway.
Before reset-seq update, nsect/lbal wait failure used to be ignored and
caused 30sec delay during detection. After reset-seq, all timeouts are
considered error conditions making libata fail to detect such ATAPI
devices.
This patch limits nsect/lbal wait to around 100ms. This should give
acceptable behavior to such ATAPI devices while not disturbing the heavily
used code path too much.
Signed-off-by: Tejun Heo <htejun@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
drivers/ata/libata-core.c | 32 +++++++++++++++++++-------------
1 files changed, 19 insertions(+), 13 deletions(-)
diff -puN drivers/ata/libata-core.c~libata-limit-post-srst-nsect-lbal-wait-to-100ms drivers/ata/libata-core.c
--- a/drivers/ata/libata-core.c~libata-limit-post-srst-nsect-lbal-wait-to-100ms
+++ a/drivers/ata/libata-core.c
@@ -3091,22 +3091,28 @@ static int ata_bus_post_reset(struct ata
}
}
- /* if device 1 was found in ata_devchk, wait for
- * register access, then wait for BSY to clear
+ /* if device 1 was found in ata_devchk, wait for register
+ * access briefly, then wait for BSY to clear.
*/
- while (dev1) {
- u8 nsect, lbal;
+ if (dev1) {
+ int i;
ap->ops->dev_select(ap, 1);
- nsect = ioread8(ioaddr->nsect_addr);
- lbal = ioread8(ioaddr->lbal_addr);
- if ((nsect == 1) && (lbal == 1))
- break;
- if (time_after(jiffies, deadline))
- return -EBUSY;
- msleep(50); /* give drive a breather */
- }
- if (dev1) {
+
+ /* Wait for register access. Some ATAPI devices fail
+ * to set nsect/lbal after reset, so don't waste too
+ * much time on it. We're gonna wait for !BSY anyway.
+ */
+ for (i = 0; i < 2; i++) {
+ u8 nsect, lbal;
+
+ nsect = ioread8(ioaddr->nsect_addr);
+ lbal = ioread8(ioaddr->lbal_addr);
+ if ((nsect == 1) && (lbal == 1))
+ break;
+ msleep(50); /* give drive a breather */
+ }
+
rc = ata_wait_ready(ap, deadline);
if (rc) {
if (rc != -ENODEV)
_
Patches currently in -mm which might be from htejun@xxxxxxxxx are
sata_promise-use-tf-interface-for-polling-nodata-commands.patch
git-libata-all.patch
pata_acpi-restore-driver.patch
libata-implement-ata_wait_after_reset.patch
libata-limit-post-srst-nsect-lbal-wait-to-100ms.patch
drivers-ata-add-sw-ncq-support-to-sata_nv-for-mcp51-mcp55-mcp61.patch
git-scsi-misc.patch
update-documentation-block-barriertxt.patch
block-drop-unnecessary-bvec-rewinding-from-flush_dry_bio_endio.patch
dma-mapping-prevent-dma-dependent-code-from-linking-on.patch
lib-add-idr_for_each.patch
lib-add-idr_for_each-fix.patch
lib-add-idr_remove_all.patch
-
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