[PATCH 2/4] scsi: hisi_sas: Modify the commit information for DSM method

From: John Garry
Date: Fri May 15 2020 - 10:18:03 EST


From: Luo Jiaxing <luojiaxing@xxxxxxxxxx>

Make it clear that BIOS may modify some register settings.

Signed-off-by: Luo Jiaxing <luojiaxing@xxxxxxxxxx>
Signed-off-by: John Garry <john.garry@xxxxxxxxxx>
---
drivers/scsi/hisi_sas/hisi_sas_v3_hw.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/drivers/scsi/hisi_sas/hisi_sas_v3_hw.c b/drivers/scsi/hisi_sas/hisi_sas_v3_hw.c
index 59b1421607dd..41e07e9f6c8a 100644
--- a/drivers/scsi/hisi_sas/hisi_sas_v3_hw.c
+++ b/drivers/scsi/hisi_sas/hisi_sas_v3_hw.c
@@ -912,11 +912,15 @@ static int hw_init_v3_hw(struct hisi_hba *hisi_hba)
return -EINVAL;
}

- /* Switch over to MSI handling , from PCI AER default */
+ /*
+ * This DSM handles some hardware-related configurations:
+ * 1. Switch over to MSI error handling in kernel
+ * 2. BIOS *may* reset some register values through this method
+ */
obj = acpi_evaluate_dsm(ACPI_HANDLE(dev), &guid, 0,
DSM_FUNC_ERR_HANDLE_MSI, NULL);
if (!obj)
- dev_warn(dev, "Switch over to MSI handling failed\n");
+ dev_warn(dev, "can not find DSM method, ignore\n");
else
ACPI_FREE(obj);

--
2.16.4