From c11428c7def52671f57089701efe878f7071b696 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Marek=20Beh=C3=BAn?= Date: Thu, 17 Feb 2022 01:08:37 +0100 Subject: [PATCH 1/3] ddr: marvell: a38x: fix BYTE_HOMOGENEOUS_SPLIT_OUT decision MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit In commit 3fc92a215b69 ("ddr: marvell: a38x: fix SPLIT_OUT_MIX state decision") I ported a cleaned up and changed version of patch mv_ddr: a380: fix SPLIT_OUT_MIX state decision In the port we removed checking for BYTE_HOMOGENEOUS_SPLIT_OUT bit, because: - the fix seemed to work without it - the bit was checked for only at one place out of two, while the second bit, BYTE_SPLIT_OUT_MIX, was checked for in both cases - without the removal it didn't work on Allied Telesis' x530 board We recently had a chance to test on more boards, and it seems that the change needs to be opposite: instead of removing the check for BYTE_HOMOGENEOUS_SPLIT_OUT from the first if() statement, the check needs to be added also to the second one - it needs to be at both places. With this change all the Turris Omnia boards I have had available to test seem to work, I didn't encounter not even one failed DDR training. As last time, I am noting that I do not understand what this code is actually doing, I haven't studied the DDR training algorithm and I suspect that no one will be able to explain it to U-Boot contributors, so we are left with this blind poking in the code with testing whether it works on several boards and hoping it doesn't break anything for anyone :-(. Signed-off-by: Marek Behún Tested-by: Chris Packham Reviewed-by: Stefan Roese --- drivers/ddr/marvell/a38x/ddr3_training_centralization.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) --- a/drivers/ddr/marvell/a38x/ddr3_training_centralization.c +++ b/drivers/ddr/marvell/a38x/ddr3_training_centralization.c @@ -180,7 +180,8 @@ static int ddr3_tip_centralization(u32 d [bit_id], EDGE_1); if (current_byte_status & - BYTE_SPLIT_OUT_MIX) { + (BYTE_SPLIT_OUT_MIX | + BYTE_HOMOGENEOUS_SPLIT_OUT)) { if (cur_start_win[bit_id] >= 64) cur_start_win[bit_id] -= 64; else @@ -197,7 +198,8 @@ static int ddr3_tip_centralization(u32 d EDGE_1); if (cur_end_win[bit_id] >= 64 && (current_byte_status & - BYTE_SPLIT_OUT_MIX)) { + (BYTE_SPLIT_OUT_MIX | + BYTE_HOMOGENEOUS_SPLIT_OUT))) { cur_end_win[bit_id] -= 64; DEBUG_CENTRALIZATION_ENGINE (DEBUG_LEVEL_INFO,