After an error condition, some ATAPI tape drives set DRQ=1 together with ERR=1
when asking the host to transfer the CDB of the next packet command (i.e. request sense).
This patch, a revised version of Alan/Mark's previous patch, adds ATA_HORKAGE_STUCK_ERR
to workaround the problem by ignoring the ERR bit and proceed sending the CDB.
Signed-off-by: Albert Lee <albertcc@xxxxxxxxxx>
Cc: Alan Cox <alan@xxxxxxxxxxxxxxxxxxx>
Cc: Mark Lord <liml@xxxxxx>
---
Revised per Alan, Mark and Tejun's comments. Tested ok with the Seagate STT8000A tape drive.
Patch against the libata-dev tree.
diff -Nrup 00_libata-dev/drivers/ata/libata-core.c 01_ide_tape_stuck_err/drivers/ata/libata-core.c
--- 00_libata-dev/drivers/ata/libata-core.c 2007-11-14 10:08:36.000000000 +0800
+++ 01_ide_tape_stuck_err/drivers/ata/libata-core.c 2007-11-14 11:20:31.000000000 +0800
@@ -5490,11 +5490,19 @@ fsm_start:
* let the EH abort the command or reset the device.
*/
if (unlikely(status & (ATA_ERR | ATA_DF))) {
- ata_port_printk(ap, KERN_WARNING, "DRQ=1 with device "
- "error, dev_stat 0x%X\n", status);
- qc->err_mask |= AC_ERR_HSM;
- ap->hsm_task_state = HSM_ST_ERR;
- goto fsm_start;
+ /* Some ATAPI tape drives forget to clear the ERR bit
+ * when doing the next command (mostly request sense).
+ * We ignore ERR here to workaround and proceed sending
+ * the CDB.
+ */
+ if (!(qc->dev->horkage & ATA_HORKAGE_STUCK_ERR)) {
+ ata_port_printk(ap, KERN_WARNING,
+ "DRQ=1 with device error, "
+ "dev_stat 0x%X\n", status);
+ qc->err_mask |= AC_ERR_HSM;
+ ap->hsm_task_state = HSM_ST_ERR;
+ goto fsm_start;
+ }
}
/* Send the CDB (atapi) or the first data block (ata pio out).
diff -Nrup 00_libata-dev/include/linux/libata.h 01_ide_tape_stuck_err/include/linux/libata.h
--- 00_libata-dev/include/linux/libata.h 2007-11-14 10:08:59.000000000 +0800
+++ 01_ide_tape_stuck_err/include/linux/libata.h 2007-11-14 11:19:32.000000000 +0800
@@ -340,6 +340,7 @@ enum {
ATA_HORKAGE_HPA_SIZE = (1 << 6), /* native size off by one */
ATA_HORKAGE_IPM = (1 << 7), /* Link PM problems */
ATA_HORKAGE_IVB = (1 << 8), /* cbl det validity bit bugs */
+ ATA_HORKAGE_STUCK_ERR = (1 << 9), /* stuck ERR on next PACKET */
/* DMA mask for user DMA control: User visible values; DO NOT
renumber */
-
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