IB/hfi1: Guard against concurrent I2C access across all chains

The discrete ASIC board design makes the two I2C chains not
independent of each other.  That is, only one chain can safely
be accessed at a time.  For discrete ASIC devices, adjust the
resource locking so that access to one I2C chain will lock both
of the chains.

Reviewed-by: Easwar Hariharan <easwar.hariharan@intel.com>
Signed-off-by: Dean Luick <dean.luick@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

diff --git a/drivers/staging/rdma/hfi1/firmware.c b/drivers/staging/rdma/hfi1/firmware.c
index 3040162..ed680fd 100644 (file)
--- a/drivers/staging/rdma/hfi1/firmware.c
+++ b/drivers/staging/rdma/hfi1/firmware.c
@@ -1413,8 +1413,15 @@ static int __acquire_chip_resource(struct hfi1_devdata *dd, u32 resource)
 
        if (resource & CR_DYN_MASK) {
                /* a dynamic resource is in use if either HFI has set the bit */
-               all_bits = resource_mask(0, resource) |
+               if (dd->pcidev->device == PCI_DEVICE_ID_INTEL0 &&
+                   (resource & (CR_I2C1 | CR_I2C2))) {
+                       /* discrete devices must serialize across both chains */
+                       all_bits = resource_mask(0, CR_I2C1 | CR_I2C2) |
+                                       resource_mask(1, CR_I2C1 | CR_I2C2);
+               } else {
+                       all_bits = resource_mask(0, resource) |
                                                resource_mask(1, resource);
+               }
                my_bit = resource_mask(dd->hfi1_id, resource);
        } else {
                /* non-dynamic resources are not split between HFIs */