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Alan Stern
e47373ec1c
The problem lies in the way the error handler uses TEST UNIT READY to tell whether error recovery has succeeded. The scsi_eh_tur function gives up after one round of retrying; after that it decides that more error recovery is needed. However TUR is liable to report sense data indicating a retry is needed when in fact error recovery has succeeded. A typical example might be SK=2, ASC=4, ASCQ=1 (Logical unit in process of becoming ready). The mere fact that we were able to get a sensible reply to the TUR should indicate that the device is working well enough to stop error recovery. I ran across a case back in January where this happened. A CD-ROM drive timed out the INQUIRY command, and a device reset fixed the blockage. But then the drive kept responding with 2/4/1 -- because it was spinning up I suppose -- until the error handler gave up and placed it offline. If the initial INQUIRY had received the 2/4/1 instead, everything would have worked okay. It doesn't seem reasonable for things to fail just because the error handler had started running. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>