e1000e: Add polling mechanism to indicate CSME DPG exit

Per guidance from the CSME architecture team, it may take
up to 1 second for unconfiguring dynamic power gating mode.
Practically it can take more time. Wait up to 2.5 seconds to indicate
dynamic power gating exit from the S0ix configuration. Detect
scenarios that take more than 1 second but less than 2.5 seconds
will emit warning message.

Signed-off-by: Sasha Neftin <sasha.neftin@intel.com>
Tested-by: Dvora Fuxbrumer <dvorax.fuxbrumer@linux.intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>

diff --git a/drivers/net/ethernet/intel/e1000e/ich8lan.h b/drivers/net/ethernet/intel/e1000e/ich8lan.h
index e59456d867dbda707089ee32ed67804fbe0dec4f..9b145f6248a8f31702881a65e2d4c02385f7535d 100644 (file)
--- a/drivers/net/ethernet/intel/e1000e/ich8lan.h
+++ b/drivers/net/ethernet/intel/e1000e/ich8lan.h
@@ -41,6 +41,7 @@
 #define E1000_FWSM_WLOCK_MAC_MASK      0x0380
 #define E1000_FWSM_WLOCK_MAC_SHIFT     7
 #define E1000_FWSM_ULP_CFG_DONE                0x00000400      /* Low power cfg done */
+#define E1000_EXFWSM_DPG_EXIT_DONE     0x00000001
 
 /* Shared Receive Address Registers */
 #define E1000_SHRAL_PCH_LPT(_i)                (0x05408 + ((_i) * 8))

diff --git a/drivers/net/ethernet/intel/e1000e/netdev.c b/drivers/net/ethernet/intel/e1000e/netdev.c
index 4fa6f9f7d1998eef7b9e2fee6cab31c6aaf1fb69..27107a927455a2f1590c19e85eaa8d469400a272 100644 (file)
--- a/drivers/net/ethernet/intel/e1000e/netdev.c
+++ b/drivers/net/ethernet/intel/e1000e/netdev.c
@@ -6481,8 +6481,10 @@ static void e1000e_s0ix_entry_flow(struct e1000_adapter *adapter)
 static void e1000e_s0ix_exit_flow(struct e1000_adapter *adapter)
 {
        struct e1000_hw *hw = &adapter->hw;
+       bool firmware_bug = false;
        u32 mac_data;
        u16 phy_data;
+       u32 i = 0;
 
        if (er32(FWSM) & E1000_ICH_FWSM_FW_VALID) {
                /* Request ME unconfigure the device from S0ix */
@@ -6490,6 +6492,28 @@ static void e1000e_s0ix_exit_flow(struct e1000_adapter *adapter)
                mac_data &= ~E1000_H2ME_START_DPG;
                mac_data |= E1000_H2ME_EXIT_DPG;
                ew32(H2ME, mac_data);
+
+               /* Poll up to 2.5 seconds for ME to unconfigure DPG.
+                * If this takes more than 1 second, show a warning indicating a
+                * firmware bug
+                */
+               while (!(er32(EXFWSM) & E1000_EXFWSM_DPG_EXIT_DONE)) {
+                       if (i > 100 && !firmware_bug)
+                               firmware_bug = true;
+
+                       if (i++ == 250) {
+                               e_dbg("Timeout (firmware bug): %d msec\n",
+                                     i * 10);
+                               break;
+                       }
+
+                       usleep_range(10000, 11000);
+               }
+               if (firmware_bug)
+                       e_warn("DPG_EXIT_DONE took %d msec. This is a firmware bug\n",
+                              i * 10);
+               else
+                       e_dbg("DPG_EXIT_DONE cleared after %d msec\n", i * 10);
        } else {
                /* Request driver unconfigure the device from S0ix */
 

diff --git a/drivers/net/ethernet/intel/e1000e/regs.h b/drivers/net/ethernet/intel/e1000e/regs.h
index 8165ba2619a4de1a20c4835e07cd7d573e7dc7a7..6c0cd8cab3ef2f21fdb547a71d5a9145fe07abed 100644 (file)
--- a/drivers/net/ethernet/intel/e1000e/regs.h
+++ b/drivers/net/ethernet/intel/e1000e/regs.h
@@ -213,6 +213,7 @@
 #define E1000_FACTPS   0x05B30 /* Function Active and Power State to MNG */
 #define E1000_SWSM     0x05B50 /* SW Semaphore */
 #define E1000_FWSM     0x05B54 /* FW Semaphore */
+#define E1000_EXFWSM   0x05B58 /* Extended FW Semaphore */
 /* Driver-only SW semaphore (not used by BOOT agents) */
 #define E1000_SWSM2    0x05B58
 #define E1000_FFLT_DBG 0x05F04 /* Debug Register */