[dpdk-dev] [PATCH v4 14/17] net/i40e/base: add EEPROM checksum verification

[Jingjing Wu <jingjing.wu@intel.com>]

This patch ensures PFs mutually exclusive access to NVM.

Signed-off-by: Jingjing Wu <jingjing.wu@intel.com>
---
 drivers/net/i40e/base/i40e_nvm.c | 14 ++++++++++----
 1 file changed, 10 insertions(+), 4 deletions(-)

diff --git a/drivers/net/i40e/base/i40e_nvm.c b/drivers/net/i40e/base/i40e_nvm.c
index 90521fa..a1e7830 100644
--- a/drivers/net/i40e/base/i40e_nvm.c
+++ b/drivers/net/i40e/base/i40e_nvm.c
@@ -749,12 +749,18 @@ enum i40e_status_code i40e_validate_nvm_checksum(struct i40e_hw *hw,
 
 	DEBUGFUNC("i40e_validate_nvm_checksum");
 
-	if (hw->flags & I40E_HW_FLAG_AQ_SRCTL_ACCESS_ENABLE)
-		ret_code = i40e_acquire_nvm(hw, I40E_RESOURCE_READ);
+	/* acquire_nvm provides exclusive NVM lock to synchronize access across
+	 * PFs. X710 uses i40e_read_nvm_word_srctl which polls for done bit
+	 * twice (first time to be able to write address to I40E_GLNVM_SRCTL
+	 * register, second to read data from I40E_GLNVM_SRDATA. One PF can see
+	 * done bit and try to write address, while another one will interpret
+	 * it as a good time to read data. It will cause invalid data to be
+	 * read.
+	 */
+	ret_code = i40e_acquire_nvm(hw, I40E_RESOURCE_READ);
 	if (!ret_code) {
 		ret_code = i40e_calc_nvm_checksum(hw, &checksum_local);
-		if (hw->flags & I40E_HW_FLAG_AQ_SRCTL_ACCESS_ENABLE)
-			i40e_release_nvm(hw);
+	i40e_release_nvm(hw);
 		if (ret_code != I40E_SUCCESS)
 			goto i40e_validate_nvm_checksum_exit;
 	} else {
-- 
2.4.11