e1000e: fix obscure comments

The interface to the device flash was modified in i219 and later HW.
This patch better describes the change and the impact on the driver.

CC: John W Linville <linville@tuxdriver.com>
Reported-by: John W Linville <linville@tuxdriver.com>
Signed-off-by: Yanir Lubetkin <yanirx.lubetkin@intel.com>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

1 files changed, 8 insertions, 4 deletions

diff --git a/drivers/net/ethernet/intel/e1000e/ich8lan.c b/drivers/net/ethernet/intel/e1000e/ich8lan.c
index 7523f510c7e4..9d81c0317433 100644
--- a/drivers/net/ethernet/intel/e1000e/ich8lan.c
+++ b/drivers/net/ethernet/intel/e1000e/ich8lan.c
@@ -603,12 +603,15 @@ static s32 e1000_init_nvm_params_ich8lan(struct e1000_hw *hw)
         u16 i;
         u32 nvm_size;
 
-        /* Can't read flash registers if the register set isn't mapped. */
         nvm->type = e1000_nvm_flash_sw;
-        /* in SPT, gfpreg doesn't exist. NVM size is taken from the
-         * STRAP register
-         */
+
         if (hw->mac.type == e1000_pch_spt) {
+                /* in SPT, gfpreg doesn't exist. NVM size is taken from the
+                 * STRAP register. This is because in SPT the GbE Flash region
+                 * is no longer accessed through the flash registers. Instead,
+                 * the mechanism has changed, and the Flash region access
+                 * registers are now implemented in GbE memory space.
+                 */
                 nvm->flash_base_addr = 0;
                 nvm_size = (((er32(STRAP) >> 1) & 0x1F) + 1)
                     * NVM_SIZE_MULTIPLIER;
@@ -618,6 +621,7 @@ static s32 e1000_init_nvm_params_ich8lan(struct e1000_hw *hw)
                 /* Set the base address for flash register access */
                 hw->flash_address = hw->hw_addr + E1000_FLASH_BASE_ADDR;
         } else {
+                /* Can't read flash registers if register set isn't mapped. */
                 if (!hw->flash_address) {
                         e_dbg("ERROR: Flash registers not mapped\n");
                         return -E1000_ERR_CONFIG;