Hello, This patchset is kicked off by kernel bz#9913 which reports hot plugging and general detection problems with WD My Book drives. WD was kind enough to provide me with these drives and I played quite a bit with a few controllers and weird cabling configurations including long cables and several genders. It was surprisingly easy to trigger link layer problems. eSATA ports often go through extra cable and gender. eSATA cables tend to be longer than internal ones and as the cables are much stiffer touching or moving the cable can easily cause enough wiggle at the connectors to cause temporary transmission problems and being outside, it's much more likely to be moved. So, with abundant link quality problems, the following problems have been identified. a. Our link speed down logic on device probing failure is broken. It somehow got masked off by a condition test which is there to prevent spurious warning messages. This prevented repeated IDENTIFY failures from triggering link speed down. b. When the condition is right (or wrong), devices succeed at negotiating 3.0Gbps but fails to actually establish link over it. This leads to frustrating repetition of hotplug events followed by failed reset attempts. libata EH needs to remember failed probe trials and speed the link down to work around this problem. c. Certain WD My Book's react badly to certain transmission errors. After a link error, it often completely shuts down the eSATA port and power down. The only way to wake it up is to remove and re-apply power. With the right cabling, this almost renders the device unusable as it completely shuts down when the host tries to transfer data. This patchset contains patches to address the above three problems. 0001-libata-fix-EH-device-failure-handling.patch 0002-libata-move-ata_dev_disable-to-libata-eh.c.patch 0003-libata-check-onlineness-before-using-SPD-in-sata_do.patch 0004-libata-clear-dev-ering-in-smarter-way.patch 0005-libata-add-spd_limit-to-sata_down_spd_limit.patch 0006-libata-improve-probe-failure-handling.patch 0007-libata-add-no-penalty-retry-request-for-EH-device-h.patch 0008-libata-implement-HORKAGE_1_5_GBPS-and-apply-it-to-W.patch 0001 fixes #a. 0002-0006 implement workaround for #b and 0007-0008 for #c. This patchset is on top of the current upstream-fixes[1]. Thanks. drivers/ata/libata-core.c | 93 +++++++++++++++++++++++++++++++++++----------- drivers/ata/libata-eh.c | 87 +++++++++++++++++++++++++++++++++++++++---- drivers/ata/libata-pmp.c | 2 drivers/ata/libata.h | 4 - include/linux/libata.h | 19 +++++---- 5 files changed, 164 insertions(+), 41 deletions(-) -- tejun [1] 4a99d95fa836e254d17910e52663ba2be7b880e7 -- 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
