The documentation for the 8070 and 8072 SPCv chip explicitly states that
a minimum of 500ms must elapse before issuing commands, otherwise the
SPCv may not process them and the firmware may get into an unrecoverable
state requiring a reboot. While the Linux guys will probably think this
is 'racy', it is called out in the chip documentation and inserting this
delay makes power management function properly.
Signed-off-by: Benjamin Rood <brood@xxxxxxxxxxxx>
---
Changes from v1 -> v2:
-Used mdelay(500) instead of a loop to facilitate required delay
-Added comment as to why this behavior exists
drivers/scsi/pm8001/pm8001_init.c | 13 +++++++++++++
1 file changed, 13 insertions(+)
diff --git a/drivers/scsi/pm8001/pm8001_init.c b/drivers/scsi/pm8001/pm8001_init.c
index 7ce7ea3..d147c41 100644
--- a/drivers/scsi/pm8001/pm8001_init.c
+++ b/drivers/scsi/pm8001/pm8001_init.c
@@ -1243,6 +1243,19 @@ static int pm8001_pci_resume(struct pci_dev *pdev)
for (i = 1; i < pm8001_ha->number_of_intr; i++)
PM8001_CHIP_DISP->interrupt_enable(pm8001_ha, i);
}
+
+ /* Chip documentation for the 8070 and 8072 SPCv */
+ /* states that a 500ms minimum delay is required */
+ /* before issuing commands. Otherwise, the firmare */
+ /* will enter an unrecoverable state. */
+
+ if (pm8001_ha->chip_id == chip_8070 ||
+ pm8001_ha->chip_id == chip_8072) {
+ mdelay(500);
+ }
+
+ /* Spin up the PHYs */
+
pm8001_ha->flags = PM8001F_RUN_TIME;
for (i = 0; i < pm8001_ha->chip->n_phy; i++) {
pm8001_ha->phy[i].enable_completion = &completion;
--
2.4.3
--
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