ice: Fix package download algorithm

Previously, the driver assumed that all signature segments would contain
one or more buffers to download. In the future, there will be signature
segments that will contain no buffers to download.

Correct download flow to allow for signature segments that have zero
download buffers and skip the download in this case.

Fixes: 3cbdb03 ("ice: Add support for E830 DDP package segment")
Reviewed-by: Przemek Kitszel <[email protected]>
Signed-off-by: Dan Nowlin <[email protected]>
Signed-off-by: Paul Greenwalt <[email protected]>
Reviewed-by: Paul Menzel <[email protected]>
Tested-by: Pucha Himasekhar Reddy <[email protected]> (A Contingent worker at Intel)
Signed-off-by: Tony Nguyen <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>

Author: DanNowlin

drivers/net/ethernet/intel/ice/ice_ddp.c

@@ -1424,14 +1424,14 @@ ice_dwnld_sign_and_cfg_segs(struct ice_hw *hw, struct ice_pkg_hdr *pkg_hdr,
 		goto exit;
 	}
 
-	conf_idx = le32_to_cpu(seg->signed_seg_idx);
-	start = le32_to_cpu(seg->signed_buf_start);
 	count = le32_to_cpu(seg->signed_buf_count);
-
 	state = ice_download_pkg_sig_seg(hw, seg);
-	if (state)
+	if (state || !count)
 		goto exit;
 
+	conf_idx = le32_to_cpu(seg->signed_seg_idx);
+	start = le32_to_cpu(seg->signed_buf_start);
+
 	state = ice_download_pkg_config_seg(hw, pkg_hdr, conf_idx, start,
 					    count);