Only the two intel drivers need this and they can easily check for
working agp support in their driver ->load callbacks.
This is the only reason why agp initialization could fail, so allows
us to rip out a bit of error handling code in the next patch.
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Dave Airlie <airlied@redhat.com>
The current values seem to be defined in a format that's specific to the
i915, gma500 and radeon drivers. To make this more generally useful, use
the values as defined in the specification.
While at it, prefix the constants with DP_ for improved namespacing.
Signed-off-by: Thierry Reding <treding@nvidia.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
- some more ppgtt prep patches from Ben
- a few fbc fixes from Ville
- power well rework from Imre
- vlv forcewake improvements from Deepak S, Ville and Jesse
- a few smaller things all over
[airlied: fixup forwcewake conflict]
* tag 'drm-intel-next-2013-11-29' of git://people.freedesktop.org/~danvet/drm-intel: (97 commits)
drm/i915: Fix port name in vlv_wait_port_ready() timeout warning
drm/i915: Return a drm_mode_status enum in the mode_valid vfuncs
drm/i915: add intel_display_power_enabled_sw() for use in atomic ctx
drm/i915: drop DRM_ERROR in intel_fbdev init
drm/i915/vlv: use parallel context restore when coming out of RC6
drm/i915/vlv: use a lower RC6 timeout on VLV
drm/i915/sdvo: Fix up debug output to not split lines
drm/i915: make sparse happy for the new vlv mmio read function
drm/i915: drop the right force-wake engine in the vlv mmio funcs
drm/i915: Fix GT wake FIFO free entries for VLV
drm/i915: Report all GTFIFODBG errors
drm/i915: Enabling DebugFS for valleyview forcewake counts
drm/i915/vlv: Valleyview support for forcewake Individual power wells.
drm/i915: Add power well arguments to force wake routines.
drm/i915: Do not attempt to re-enable an unconnected primary plane
drm/i915: add a debugfs entry for power domain info
drm/i915: add a default always-on power well
drm/i915: don't do BDW/HSW specific powerdomains init on other platforms
drm/i915: protect HSW power well check with IS_HASWELL in redisable_vga
drm/i915: use IS_HASWELL/BROADWELL instead of HAS_POWER_WELL
...
Conflicts:
drivers/gpu/drm/i915/intel_display.c
The GMCH_CTRL register (or MGCC in the spec) is at a different address
on Sandybridge, and the address to which we currently write to is
undefined. These stray writes appear to upset (hard hang) my Ivybridge
machine whilst it is in UEFI mode.
Note that the register is still marked as locked RO on Sandybridge, so
vgaarb is still dysfunctional.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: stable@vger.kernel.org
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
We use this hook starting from ILK onwards, so change the prefix
accordingly. Also rename functions/struct names used from
haswell_update_wm that are relevant to ILK already.
No functional change.
Signed-off-by: Imre Deak <imre.deak@intel.com>
Reviewed-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Reviewed-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
No functional change.
Signed-off-by: Imre Deak <imre.deak@intel.com>
Reviewed-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Apparently always enabling the sprite scaler magically made
sprites work on ILK in the past.
I think the real reason for the failure was missing sprite
watermark programming, and enabling the scaler effectively
disabled LP1+ watermarks, which was enough to keep things going.
Or it might be that the hardware more or less ignores watermarks
for scaled sprites since things seem to work even if I leave
sprite watermarks at 0 and disable all other planes except the
sprite.
In any case, we left the scaler always on but then failed to
check whether we might be exceeding the scaler's source size
limits. That caused the sprite to fail when a sufficiently
large unscaled image was being displayed.
Now that we're getting proper watermark programming for ILK, we
can keep the scaler disabled unless we need to do actual scaling.
This reverts commit 8aaa81a166.
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Imre Deak <imre.deak@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
As the watermark registers aren't double bufferd, clearing the
watermarks immediately after writing the sprite registers can be
hazardous.
Until we have something better, add a wait for vblank between the
two steps to make sure the sprite no longer needs the watermark
levels before we clear them.
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Imre Deak <imre.deak@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
When color keying is used, the primary may not be invisible even though
the sprite fully covers it. So check for color keying before deciding to
disable the primary plane.
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Imre Deak <imre.deak@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
We now have a very clear method of disabling LP1+ wartermarks,
and we can actually detect if we actually did disable them, or
if they were already disabled. Use that to clean up the
WaCxSRDisabledForSpriteScaling:ivb handling.
I was hoping to apply the workaround in a way that wouldn't
require a blocking wait, but sadly IVB really does appear to
require LP1+ watermarks to be off for an entire frame before
enabling sprite scaling. Simply disabling LP1+ watermarks
during the previous frame is not enough, no matter how early
in the frame we do it :(
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Imre Deak <imre.deak@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
The new HSW watermark code can now handle ILK/SNB/IVB as well, so
switch them over. Kill the old code.
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Imre Deak <imre.deak@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
ILK doesn't like if we just write the LP1+ watermarks registers with 0.
We need to just disable the watermarks by clearing the enable bit. Use
that method also when disabling LP1+ watermarks in init_clock_gating.
It looks like disabling the sprite LP1 watermarks can cause underruns
even if we just toggle the WM1S_LP_EN bit. So treat that bit like the
actual watermark numbers and avoid setting it to 0 immediately.
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Imre Deak <imre.deak@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Linetime watermarks don't exist on ILK/SNB/IVB, so don't compute them
except on HSW.
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Imre Deak <imre.deak@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
ILK has a bunch of issues with FBC. First of all, BSpec tells us that
FBC WM should never be enabled. Secondly when FBC is enabled
with FBC WM disabled, LP2+ watermarks must be disabled.
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Imre Deak <imre.deak@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Multi-pipe LP1+ watermarks are a HSW+ feature, so let's not do it on
earlier generations.
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Imre Deak <imre.deak@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
On ILK disabling LP1+ watermarks must be done carefully to avoid
underruns. If we just write 0 to the register in the middle of the scan
cycle we often get an underrun. So instead we have to leave the actual
watermark levels in the register intact, and just toggle the enable bit.
Presumably the hardware takes a while to get out of low power mode, and
so the watermark level need to stay valid until that time.
We also have to be careful with the WM1S_LP_EN bit. It seems the
hardware more or less treats it like the actual watermarks numbers, and
so we must not toggle it too soon. Just leave it alone when disabling
the LP1+ watermarks.
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Imre Deak <imre.deak@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
ILK/SNB don't have LP2+ watermarks for sprites. Also the LP1 sprite
watermark register has its own enable bit. Take these differences
into account when programming the LP1+ registers.
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Imre Deak <imre.deak@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
On ILK/SNB only LP0/1 watermarks can be enabled when sprites are
enabled, and on ILK/SNB/IVB sprite scaling is limited to LP0 only.
So we can avoid computing the extra levels we're never going to use.
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Imre Deak <imre.deak@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Add a new function ilk_wm_lp_latency() which will tell us what to write
into the WM_LPx register latency field. HSW is different from erlier
gens in this regard.
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Imre Deak <imre.deak@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
On IVB the display data buffer partitioning control lives in the
DISP_ARB_CTL2 register. Add the relevant defines/code for it.
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Imre Deak <imre.deak@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Otherwise we don't kick out firmware framebuffers like vesafb and
efifb when CONFIG_DRM_I915_FBDEV=n but CONFIG_FB=y.
There's still the pesky issue with vgacon which we should somehow
replace with the dummy console at least. We have a similar issue at
module un/reload, since vgacon state is terminally botched after
i915.ko has loaded in modeset mode. But this gets us a step further at
least.
v2: Use IS_ENABLED - I always get this wrong for tristates. Spotted by
Jani.
Reported-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Noticed while reviewing a patch and couldn't resist the OCD.
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Aside from the fact that it leaves confusing dumps on error capture, it
is entirely unnecessary, and potentially harmful in cases like BDW,
where the instruction has changed.
In reality (seemingly), this will have no behavioral impact.
Signed-off-by: Ben Widawsky <ben@bwidawsk.net>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
A few command were out of numerical order and had different spacing. Put
them back in numerical order, with proper spacing.
Signed-off-by: Ben Widawsky <ben@bwidawsk.net>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
We only need to init the reg offset for DPIO once, but we need to reset
DPIO at resume time and at init time.
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Just add an early init since we may need to access DPIO regs early on.
The init call in modeset_init_hw is also needed for the resume case,
when we need to reset DPIO to keep things happy.
v2: split reset and reg init
v3: split patches (Daniel)
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
The whole file is wrapped around in #if defined(CONFIG_DEBUG_FS) anyway,
so skip the file at the build level already.
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
In case of error, the function debugfs_create_file() returns NULL
pointer not ERR_PTR() if debugfs is enabled. The IS_ERR() test in
the return value check should be replaced with NULL test.
Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
We don't actually do anything with the information yet, but parse and
log what's in the VBT.
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@gmail.com>
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@gmail.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Now that all the infrastructure is in place and all the tests from
pm_pc8 pass, we can finally enable the feature.
Signed-off-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@gmail.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
So we'll get a fault when someone tries to access the mmap, then we'll
wake up from D3.
v2: - Rebase
v3: - Use gtt active/inactive
Testcase: igt/pm_pc8/gem-mmap-gtt
Signed-off-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@gmail.com>
[danvet: Add comment + WARN as discussed with Paulo on irc.]
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
The hangcheck function requires the hardware to be working, and if
we're suspending we're going to put the HW in D3 state.
Signed-off-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@gmail.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
In the current code, at haswell_modeset_global_resources, first we
decide if we want to enable/disable the power well, then we decide if
we want to enable/disable PC8. On the case where we're enabling PC8
this works fine, but on the case where we disable PC8 due to a non-eDP
monitor being enabled, we first enable the power well and then disable
PC8. Although wrong, this doesn't seem to be causing any problems now,
and we don't even see anything in dmesg. But the patches for runtime
D3 turn this problem into a real bug, so we need to fix it.
This fixes the "modeset-non-lpsp" subtest from the "pm_pc8" test from
intel-gpu-tools.
v2: - Rebase (i915_disable_power_well).
v3: - More reabase.
v4: - Rebase on top of -fixes instead of -nightly.
This is commit d62292c8f7 in -next, but
we need it in -fixes to address Dave's report.
Signed-off-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@gmail.com>
Reported-by: Dave Jones <davej@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Currently, PC8 is enabled at modeset_global_resources, which is called
after intel_modeset_update_state. Due to this, there's a small race
condition on the case where we start enabling PC8, then do a modeset
while PC8 is still being enabled. The racing condition triggers a WARN
because intel_modeset_update_state will mark the CRTC as enabled, then
the thread that's still enabling PC8 might look at the data structure
and think that PC8 is being enabled while a pipe is enabled. Despite
the WARN, this is not really a bug since we'll wait for the
PC8-enabling thread to finish when we call modeset_global_resources.
The spec says the CRTC cannot be enabled when we disable LCPLL, so we
had a check for crtc->base.enabled. If we change to crtc->active we
will still prevent disabling LCPLL while the CRTC is enabled, and we
will also prevent the WARN above.
This is a replacement for the previous patch named
"drm/i915: get/put PC8 when we get/put a CRTC"
Testcase: igt/pm_pc8/modeset-lpsp-stress-no-wait
Signed-off-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
(cherry picked from commit 798183c547
from -next due to Dave's report.)
Reported-by: Dave Jones <davej@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
WaVSRefCountFullforceMissDisable and
WaDSRefCountFullforceMissDisable
VS is a carry-over from HSW, and DS is likely not used by anyone yet.
Cc: Kenneth Graunke <kenneth@whitecape.org>
Signed-off-by: Ben Widawsky <ben@bwidawsk.net>
Reviewed-by: Damien Lespiau <damien.lespiau@intel.com>
[danvet: Line of 106 chars is too long. Really.]
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
I stumbled on to some unimplemented errata. To be honest, I am not
really sure of the impact, just that the docs say to do.
No w/a name for this one.
v2: v1 was a stale thing which should have never seen the light of day.
(Haihao)
Cc: Kenneth Graunke <kenneth@whitecape.org>
Signed-off-by: Ben Widawsky <ben@bwidawsk.net>
Reviewed-by: Damien Lespiau <damien.lespiau@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Not all registers need forcewake even if they're not shadowed.
Add the missing check to gen8_writeX() to avoid needless forcewake
usage when writing eg. display registers.
v2: Use straight up <0x40000 check instead of NEEDS_FORCE_WAKE()
Reviewed-by: Ben Widawsky <ben@bwidawsk.net>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
The BIOS or someone else might have done something bad and there
might be old GT FIFO erros reported in GTFIFODBG. Clear those out
in intel_uncore_early_sanitize() to make sure we don't mistake them
for our problems.
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
If test is running, irq_get was not called so we should gain
balance by not doing irq_put
"So the rule is: if you access unlocked values, you use ACCESS_ONCE().
You don't say "but it can't matter". Because you simply don't know."
-- Linus
v2: use local variable so it can't change during test (Chris)
v3: update commit msg and use ACCESS_ONCE (Ville)
Signed-off-by: Mika Kuoppala <mika.kuoppala@intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Don't touch DPFC_RECOMP_CTL on FBC2, use RMW to update
the FBC_CONTROL on FBC1 to make it easier for people to
experiment with different numbers. Also fix the interval
mask for FBC1.
v2: Rebased
Reviewed-by: Imre Deak <imre.deak@intel.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
All mobile gen2 and gen3 chipsets should have FBC1, and the code
should now handle them all. So just set has_fbc=true for all such
chipsets.
Note that fbc is still disabled by default for now.
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Imre Deak <imre.deak@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Gen2 and gen3 don't have the FBC_CONTROL2 register, so don't
touch it.
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Imre Deak <imre.deak@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
On gen2 the compressed frame buffer pitch is specified in 32B units
rather than the 64B units used on gen3+.
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Imre Deak <imre.deak@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
The first piece, intel_ddi_pll_select, finds a PLL and assigns it to
the CRTC, but doesn't write any register. It can also fail in case it
doesn't find a PLL.
The second piece, intel_ddi_pll_enable, uses the information stored by
intel_ddi_pll_select to actually enable the PLL by writing to its
register. This function can't fail. We also have some refcount sanity
checks here.
The idea is that one day we'll remove all the functions that touch
registers from haswell_crtc_mode_set to haswell_crtc_enable, so we'll
call intel_ddi_pll_select at haswell_crtc_mode_set and then call
intel_ddi_pll_enable at haswell_crtc_enable. Since I'm already
touching this code, let's take care of this particular split today.
v2: - Clock on the debug message is in KHz
- Add missing POSTING_READ
Signed-off-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Reviewed-by: Damien Lespiau <damien.lespiau@intel.com>
[danvet: Bikeshed comments.]
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Commit 094f9a54e3 ("drm/i915: Fix __wait_seqno to use true infinite
timeouts") added support for __wait_seqno to detect missing interrupts and
go around them by polling. As there is also timeout detection in
__wait_seqno, the polling and timeout detection were done with the same
timer.
When there has been missed interrupts and polling is needed, the timer is
set to trigger in (now + 1) jiffies in future, instead of the caller
specified timeout.
Now when io_schedule() returns, we calculate the jiffies left to timeout
using the timer expiration value. As the current jiffies is now bound to be
always equal or greater than the expiration value, the timeout_jiffies will
become zero or negative and we return -ETIME to caller even tho the
timeout was never reached.
Fix this by decoupling timeout calculation from timer expiration.
v2: Commit message with some sense in it (Chris Wilson)
v3: add parenthesis on timeout_expire calculation
v4: don't read jiffies without timeout (Chris Wilson)
Signed-off-by: Mika Kuoppala <mika.kuoppala@intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Fixes regression introduced by:
commit bf51d5e2cd
Author: Paulo Zanoni <paulo.r.zanoni at intel.com>
Date: Wed Jul 3 17:12:13 2013 -0300
drm/i915: switch disable_power_well default value to 1
The bug I'm seeing can be reproduced with:
- Have vgacon configured/enabled
- Make sure the power well gets disabled, then enabled. You can
check this by seeing the messages print by hsw_set_power_well
- Stop your display manager
- echo 0 > /sys/class/vtconsole/vtcon1/bind
I can easily reproduce this by blacklising snd_hda_intel and booting
with eDP+HDMI.
If you do this and then look at dmesg, you'll see we're printing
infinite "Unclaimed register" messages. This is happening because
we're stuck on an infinite loop inside console_unlock(), which is
calling many functions from vgacon.c. And the code that's triggering
the error messages is from vgacon_set_cursor_size().
After we re-enable the power well, every time we read/write the VGA
address 0x3d5 we get an "unclaimed register" interrupt (ERR_INT) and
print error messages. If we write anything to the VGA MSR register (it
doesn't really matter which value you write to bit 0), any
reads/writes to 0x3d5 _don't_ trigger the "unclaimed register" errors
anymore (even if MSR bit 0 is zero). So what happens with the current
code is that when we unbind i915 and bind vgacon, we call
console_unlock(). Function console_unlock() is responsible for
printing any messages that were supposed to be print when the console
was locked, so it calls the TTY layer, which calls the console layer,
which calls vgacon to print the messages. At this point, vgacon
eventually calls vgacon_set_cursor_size(), which touches 0x3d5, which
triggers unclaimed register interrupts. The problem is that when we
get these interrupts, we print the error messages, so we add more work
to console_unlock(), which will try to print it again, and then call
vgacon again, trigger a new interrupt, which will put more stuff to
the buffer, and then we'll be stuck at console_unlock() forever.
If you patch intel_uncore.c to not print anything when we detect
unclaimed registers, we won't get into the console_unlock() infinite
loop and the driver unbind will work just fine. We will still be
getting interrupts every time vgacon touches those registers, but we
will survive. This is a valid experiment, but IMHO it's not the real
fix: if we don't print any error messages we will still keep getting
the interrupts, and if we disable ERR_INT we won't get the interrupt
anymore, but we will also stop getting all the other error interrupts.
I talked about this problem with the HW engineer and his
recommendation is "So don't do any VGA I/O or memory access while the
power well is disabled, and make to re-program MSR after enabling the
power well and before using VGA I/O or memory accesses.".
Notice that this is just a partial fix to fd.o #67813. This fixes the
case where the power well is already enabled when we unbind, not when
it's disabled when we unbind.
V2: - Rebase (first version was sent in September).
V3: - Complete rewrite of the same fix: smaller implementation,
improved commit message.
Testcase: igt/drv_module_reload
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=67813
Signed-off-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Reviewed-by: Damien Lespiau <damien.lespiau@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
I want to add more code to the post_enable function.
Signed-off-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Reviewed-by: Damien Lespiau <damien.lespiau@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
It was supposed to have been killed on the same commit that killed the
function, e1264ebe9f, but I guess the
intel_drv.h reorganization accidentally brought it back.
Signed-off-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Reviewed-by: Damien Lespiau <damien.lespiau@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
