iwlwifi: pcie: provide a way to stop configuration if it is forbidden

The firmware debug infrastructure allows the user to
provide a firmware that will toggle a few registers to
configure the debugging capabilities.
On certain devices, certain operations are forbidden.
Executing a forbidden operation will cause the hardware to
die in a way that only driver unload / load will bring it
back to life.
Fortunately, there is a way to know in advance if those
operations will be accepted by the device. This is where
the new PRPH_BLOCKBIT operation plays its role. If the bit
X from PRPH register Y is set, then we should prevent any
further register configuration. When that happens, drop a
line in the kernel log since this is really an error state:
the user won't have his device configured as he expected.
Add operations that will be used in the future:
INDIRECT_ASSIGN, INDIRECT_SETBIT, and INDIRECT_CLEARBIT.

Other debugging configurations (such as destination
configuration for the monitor) will take place in any case.

Signed-off-by: Haim Dreyfuss <haim.dreyfuss@intel.com>
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>

diff --git a/drivers/net/wireless/iwlwifi/iwl-fw-file.h b/drivers/net/wireless/iwlwifi/iwl-fw-file.h
index f99ec4e..884825c 100644 (file)
--- a/drivers/net/wireless/iwlwifi/iwl-fw-file.h
+++ b/drivers/net/wireless/iwlwifi/iwl-fw-file.h
@@ -412,6 +412,12 @@ enum iwl_fw_dbg_reg_operator {
        PRPH_ASSIGN,
        PRPH_SETBIT,
        PRPH_CLEARBIT,
+
+       INDIRECT_ASSIGN,
+       INDIRECT_SETBIT,
+       INDIRECT_CLEARBIT,
+
+       PRPH_BLOCKBIT,
 };
 
 /**

diff --git a/drivers/net/wireless/iwlwifi/pcie/trans.c b/drivers/net/wireless/iwlwifi/pcie/trans.c
index 88ab79f..46e900e 100644 (file)
--- a/drivers/net/wireless/iwlwifi/pcie/trans.c
+++ b/drivers/net/wireless/iwlwifi/pcie/trans.c
@@ -881,6 +881,14 @@ static void iwl_pcie_apply_destination(struct iwl_trans *trans)
                case PRPH_CLEARBIT:
                        iwl_clear_bits_prph(trans, addr, BIT(val));
                        break;
+               case PRPH_BLOCKBIT:
+                       if (iwl_read_prph(trans, addr) & BIT(val)) {
+                               IWL_ERR(trans,
+                                       "BIT(%u) in address 0x%x is 1, stopping FW configuration\n",
+                                       val, addr);
+                               goto monitor;
+                       }
+                       break;
                default:
                        IWL_ERR(trans, "FW debug - unknown OP %d\n",
                                dest->reg_ops[i].op);
@@ -888,6 +896,7 @@ static void iwl_pcie_apply_destination(struct iwl_trans *trans)
                }
        }
 
+monitor:
        if (dest->monitor_mode == EXTERNAL_MODE && trans_pcie->fw_mon_size) {
                iwl_write_prph(trans, le32_to_cpu(dest->base_reg),
                               trans_pcie->fw_mon_phys >> dest->base_shift);