diff options
| author | Arthur Heymans <arthur@aheymans.xyz> | 2018-05-26 15:05:09 +0200 |
|---|---|---|
| committer | Patrick Georgi <pgeorgi@google.com> | 2018-06-14 09:36:04 +0000 |
| commit | 5a9dbde59c5ef1c8aa1a0a96e8eeedd108c5ae5d (patch) | |
| tree | 91d2320a826e5249d61981c8c7b3cb06cc7d4a66 /src/northbridge/intel/x4x | |
| parent | 0602ce67a6c933662998a0faabb64409fc71a88e (diff) | |
nb/intel/x4x: Work around a quirk
It looks like this hardware has a bug where the display controller
does not work properly when dram is clocked 533MHz and the channels
are configured in non-stacked mode.
The workaround is to select stacked mode in this configuration.
Change-Id: I6f37ce15a4e98a4cdbd6d893f22846a65c8be021
Signed-off-by: Arthur Heymans <arthur@aheymans.xyz>
Reviewed-on: https://review.coreboot.org/26564
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Patrick Rudolph <siro@das-labor.org>
Reviewed-by: Felix Held <felix-coreboot@felixheld.de>
Diffstat (limited to 'src/northbridge/intel/x4x')
| -rw-r--r-- | src/northbridge/intel/x4x/raminit.c | 21 |
1 files changed, 21 insertions, 0 deletions
diff --git a/src/northbridge/intel/x4x/raminit.c b/src/northbridge/intel/x4x/raminit.c index 9e649b0ec4..d41b74c8db 100644 --- a/src/northbridge/intel/x4x/raminit.c +++ b/src/northbridge/intel/x4x/raminit.c @@ -352,6 +352,26 @@ static void select_cas_dramfreq_ddr3(struct sysinfo *s, } } +/* With DDR3 and 533MHz mem clock and an enabled internal gfx device the display + is not usable in non stacked mode, so select stacked mode accordingly */ +static void workaround_stacked_mode(struct sysinfo *s) +{ + u32 deven; + /* Only a problem on DDR3 */ + if (s->spd_type == DDR2) + return; + /* Does not matter if only one channel is populated */ + if (!CHANNEL_IS_POPULATED(s->dimms, 0) + || !CHANNEL_IS_POPULATED(s->dimms, 1)) + return; + if (s->selected_timings.mem_clk != MEM_CLOCK_1066MHz) + return; + /* IGD0EN gets disabled if not present before this code runs */ + deven = pci_read_config32(PCI_DEV(0, 0, 0), D0F0_DEVEN); + if (deven & IGD0EN) + s->stacked_mode = 1; +} + static int ddr3_save_dimminfo(u8 dimm_idx, u8 *raw_spd, struct abs_timings *saved_timings, struct sysinfo *s) { @@ -544,6 +564,7 @@ static void decode_spd_select_timings(struct sysinfo *s) else select_cas_dramfreq_ddr3(s, &saved_timings); select_discrete_timings(s, &saved_timings); + workaround_stacked_mode(s); } static void find_dimm_config(struct sysinfo *s) |