[PATCH 2/2] switchtec: fix minor bug with partition id register

[Logan Gunthorpe]

When a switch endpoind is configured without NTB the mmio_ntb registers
will read all zeros. However, in corner case configurations where the
partition ID is not zero and NTB is not enabled then the code will have
the wrong partition ID and this causes the driver to use the wrong
set of drivers. To fix this we simply take the partition ID from the
system info region.

Signed-off-by: Logan Gunthorpe <logang@xxxxxxxxxxxx>
Reported-by: Dingbao Chen <dingbao.chen@xxxxxxxxxxxxx>
---
 drivers/pci/switch/switchtec.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/pci/switch/switchtec.c b/drivers/pci/switch/switchtec.c
index abaa227a..f6a6340 100644
--- a/drivers/pci/switch/switchtec.c
+++ b/drivers/pci/switch/switchtec.c
@@ -1441,12 +1441,15 @@ static int switchtec_init_pci(struct switchtec_dev *stdev,
 	stdev->mmio_sys_info = stdev->mmio + SWITCHTEC_GAS_SYS_INFO_OFFSET;
 	stdev->mmio_flash_info = stdev->mmio + SWITCHTEC_GAS_FLASH_INFO_OFFSET;
 	stdev->mmio_ntb = stdev->mmio + SWITCHTEC_GAS_NTB_OFFSET;
-	stdev->partition = ioread8(&stdev->mmio_ntb->partition_id);
+	stdev->partition = ioread8(&stdev->mmio_sys_info->partition_id);
 	stdev->partition_count = ioread8(&stdev->mmio_ntb->partition_count);
 	stdev->mmio_part_cfg_all = stdev->mmio + SWITCHTEC_GAS_PART_CFG_OFFSET;
 	stdev->mmio_part_cfg = &stdev->mmio_part_cfg_all[stdev->partition];
 	stdev->mmio_pff_csr = stdev->mmio + SWITCHTEC_GAS_PFF_CSR_OFFSET;
 
+	if (stdev->partition_count < 1)
+		stdev->partition_count = 1;
+
 	init_pff(stdev);
 
 	pci_set_drvdata(pdev, stdev);
-- 
2.1.4