Message ID | 20220217000837.13003-1-kabel@kernel.org |
---|---|
State | Accepted |
Commit | a163db9fbaa9004bc461d8b1c6b648c674c25f09 |
Delegated to: | Stefan Roese |
Headers | show |
Series | [u-boot-marvell] ddr: marvell: a38x: fix BYTE_HOMOGENEOUS_SPLIT_OUT decision | expand |
On 2/17/22 01:08, Marek Behún wrote: > From: Marek Behún <marek.behun@nic.cz> > > 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 <marek.behun@nic.cz> > Tested-by: Chris Packham <judge.packham@gmail.com> > Reviewed-by: Stefan Roese <sr@denx.de> Applied to u-boot-marvell/master Thanks, Stefan > --- > drivers/ddr/marvell/a38x/ddr3_training_centralization.c | 6 ++++-- > 1 file changed, 4 insertions(+), 2 deletions(-) > > diff --git a/drivers/ddr/marvell/a38x/ddr3_training_centralization.c b/drivers/ddr/marvell/a38x/ddr3_training_centralization.c > index 42308b6965..be9f985f22 100644 > --- 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 dev_num, u32 mode) > [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 dev_num, u32 mode) > 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, Viele Grüße, Stefan Roese
diff --git a/drivers/ddr/marvell/a38x/ddr3_training_centralization.c b/drivers/ddr/marvell/a38x/ddr3_training_centralization.c index 42308b6965..be9f985f22 100644 --- 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 dev_num, u32 mode) [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 dev_num, u32 mode) 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,