ice: wait before enabling TSPLL

To ensure proper operation, wait for 10 to 20 microseconds before
enabling TSPLL.

Adjust wait time after enabling TSPLL from 1-5 ms to 1-2 ms.

Those values are empirical and tested on multiple HW configurations.

Reviewed-by: Milena Olech <milena.olech@intel.com>
Signed-off-by: Karol Kolacinski <karol.kolacinski@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>

diff --git a/drivers/net/ethernet/intel/ice/ice_tspll.c b/drivers/net/ethernet/intel/ice/ice_tspll.c
index e7b44e703d7c0966414e119f861ee1ab165d9293..abd9f4ff2f5563e35dd8e8fa551eb944d8f5802a 100644 (file)
--- a/drivers/net/ethernet/intel/ice/ice_tspll.c
+++ b/drivers/net/ethernet/intel/ice/ice_tspll.c
@@ -261,6 +261,9 @@ static int ice_tspll_cfg_e82x(struct ice_hw *hw, enum ice_tspll_freq clk_freq,
        if (err)
                return err;
 
+       /* Wait to ensure everything is stable */
+       usleep_range(10, 20);
+
        /* Finally, enable the PLL */
        r24 |= ICE_CGU_R23_R24_TSPLL_ENABLE;
 
@@ -268,8 +271,8 @@ static int ice_tspll_cfg_e82x(struct ice_hw *hw, enum ice_tspll_freq clk_freq,
        if (err)
                return err;
 
-       /* Wait to verify if the PLL locks */
-       usleep_range(1000, 5000);
+       /* Wait at least 1 ms to verify if the PLL locks */
+       usleep_range(USEC_PER_MSEC, 2 * USEC_PER_MSEC);
 
        err = ice_read_cgu_reg(hw, ICE_CGU_RO_BWM_LF, &val);
        if (err)
@@ -445,6 +448,9 @@ static int ice_tspll_cfg_e825c(struct ice_hw *hw, enum ice_tspll_freq clk_freq,
        if (err)
                return err;
 
+       /* Wait to ensure everything is stable */
+       usleep_range(10, 20);
+
        /* Finally, enable the PLL */
        r23 |= ICE_CGU_R23_R24_TSPLL_ENABLE;
 
@@ -452,8 +458,8 @@ static int ice_tspll_cfg_e825c(struct ice_hw *hw, enum ice_tspll_freq clk_freq,
        if (err)
                return err;
 
-       /* Wait to verify if the PLL locks */
-       usleep_range(1000, 5000);
+       /* Wait at least 1 ms to verify if the PLL locks */
+       usleep_range(USEC_PER_MSEC, 2 * USEC_PER_MSEC);
 
        err = ice_read_cgu_reg(hw, ICE_CGU_RO_LOCK, &val);
        if (err)