+++ /dev/null
-From 3fc92a215b69ad448c151489228eb340df9a8703 Mon Sep 17 00:00:00 2001
-From: =?UTF-8?q?Marek=20Beh=C3=BAn?= <marek.behun@nic.cz>
-Date: Wed, 12 Jan 2022 17:06:59 +0100
-Subject: [PATCH] ddr: marvell: a38x: fix SPLIT_OUT_MIX state decision
-MIME-Version: 1.0
-Content-Type: text/plain; charset=UTF-8
-Content-Transfer-Encoding: 8bit
-
-This is a cleaned up and fixed version of a patch
- mv_ddr: a380: fix SPLIT_OUT_MIX state decision
-
- in each pattern cycle the bus state can be changed
- in order to avoide it, need to back to the same bus state on each
- pattern cycle
-by
- Moti Boskula <motib@marvell.com>
-
-The original patch is not in Marvell's mv-ddr-marvell repository. It was
-gives to us by Marvell to fix an issues with DDR training on some
-boards, but it cannot be applied as is to mv-ddr-marvell, because it is
-a very dirty draft patch that would certainly break other things, mainly
-DDR4 training code in mv-ddr-marvell, since it changes common functions.
-
-I have cleaned up the patch and removed stuff that seemed unnecessary
-(when removed, it still fixed things). Note that I don't understand
-completely what the code does exactly, since I haven't studied the DDR
-training code extensively (and I suspect that no one besides some few
-people in Marvell understand the code completely).
-
-Anyway after the cleanup the patch still fixes isssues with DDR training
-on the failing boards.
-
-There was also a problem with the original patch on some of the Allied
-Telesis' x530 boards, reported by Chris Packham. I have asked Chris to
-send me some logs, and managed to fix it:
-- if you look at the change, you'll notice that it introduces
- subtraction of cur_start_win[] and cur_end_win[] members, depending on
- a bit set in the current_byte_status variable
-- the original patch subtracted cur_start_win[] if either
- BYTE_SPLIT_OUT_MIX or BYTE_HOMOGENEOUS_SPLIT_OUT bits were set, but
- subtracted cur_end_win[] only if the first one (BYTE_SPLIT_OUT_MIX)
- was set
-- from Chris Packham logs I discovered that the x530 board where the
- original patch introduced DDR training failure, only the
- BYTE_HOMOGENEOUS_SPLIT_OUT bit was set, and on our boards where the
- patch is needed only the BYTE_SPLIT_OUT_MIX is set in the
- current_byte_status variable
-- this led me to the hypothesis that both cur_start_win[] and
- cur_end_win[] should be subtracted only if BYTE_SPLIT_OUT_MIX bit is
- set, the BYTE_HOMOGENEOUS_SPLIT_OUT bit shouldn't be considered at all
-- this hypothesis also gains credibility when considering the commit
- title ("fix SPLIT_OUT_MIX state decision")
-
-Hopefully this will fix things without breaking anything else.
-
-Signed-off-by: Marek Behún <marek.behun@nic.cz>
-Reviewed-by: Stefan Roese <sr@denx.de>
-Tested-by: Chris Packham <judge.packham@gmail.com>
----
- .../a38x/ddr3_training_centralization.c | 26 +++++++++++++++++++
- 1 file changed, 26 insertions(+)
-
---- a/drivers/ddr/marvell/a38x/ddr3_training_centralization.c
-+++ b/drivers/ddr/marvell/a38x/ddr3_training_centralization.c
-@@ -55,6 +55,7 @@ static int ddr3_tip_centralization(u32 d
- enum hws_training_ip_stat training_result[MAX_INTERFACE_NUM];
- u32 if_id, pattern_id, bit_id;
- u8 bus_id;
-+ u8 current_byte_status;
- u8 cur_start_win[BUS_WIDTH_IN_BITS];
- u8 centralization_result[MAX_INTERFACE_NUM][BUS_WIDTH_IN_BITS];
- u8 cur_end_win[BUS_WIDTH_IN_BITS];
-@@ -166,6 +167,10 @@ static int ddr3_tip_centralization(u32 d
- result[search_dir_id][7]));
- }
-
-+ current_byte_status =
-+ mv_ddr_tip_sub_phy_byte_status_get(if_id,
-+ bus_id);
-+
- for (bit_id = 0; bit_id < BUS_WIDTH_IN_BITS;
- bit_id++) {
- /* check if this code is valid for 2 edge, probably not :( */
-@@ -174,11 +179,32 @@ static int ddr3_tip_centralization(u32 d
- [HWS_LOW2HIGH]
- [bit_id],
- EDGE_1);
-+ if (current_byte_status &
-+ BYTE_SPLIT_OUT_MIX) {
-+ if (cur_start_win[bit_id] >= 64)
-+ cur_start_win[bit_id] -= 64;
-+ else
-+ cur_start_win[bit_id] = 0;
-+ DEBUG_CENTRALIZATION_ENGINE
-+ (DEBUG_LEVEL_INFO,
-+ ("pattern %d IF %d pup %d bit %d subtract 64 adll from start\n",
-+ pattern_id, if_id, bus_id, bit_id));
-+ }
- cur_end_win[bit_id] =
- GET_TAP_RESULT(result
- [HWS_HIGH2LOW]
- [bit_id],
- EDGE_1);
-+ if (cur_end_win[bit_id] >= 64 &&
-+ (current_byte_status &
-+ BYTE_SPLIT_OUT_MIX)) {
-+ cur_end_win[bit_id] -= 64;
-+ DEBUG_CENTRALIZATION_ENGINE
-+ (DEBUG_LEVEL_INFO,
-+ ("pattern %d IF %d pup %d bit %d subtract 64 adll from end\n",
-+ pattern_id, if_id, bus_id, bit_id));
-+ }
-+
- /* window length */
- current_window[bit_id] =
- cur_end_win[bit_id] -
projects / openwrt / staging / chunkeey.git / blobdiff