Gen3+ is 13 bits (12:0), and on gen2 only 12 (11:0). For both the high
bits are marked reserved, read-only so continue to mask them. Bit 31
is not reserved and has a meaning.
Signed-off-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-Off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
... we actually use it.
Unfortunately we can't reset both at the same time without also
resetting the display unit, so do render and media separately.
Also replace magic constants with proper #defines.
Signed-Off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
I've missed this one.
v2: Chris Wilson noticed another register.
v3: Color choice improvements.
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-Off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
... and put them to so good use.
Note that there's functional change in vlv clock gating code, we now
no longer spuriously read back the current value of the bit. According
to Bspec the high bits should always read zero, so ORing this in
should have no effect.
Reviewed-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Eugeni Dodonov <eugeni.dodonov@intel.com>
Signed-Off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
PCH PLLs aren't required for outputs on the CPU, so we shouldn't just
treat them as part of the pipe.
So split the code out and manage PCH PLLs separately, allocating them
when needed or trying to re-use existing PCH PLL setups when the timings
match.
v2: add num_pch_pll field to dev_priv (Daniel)
don't NULL the pch_pll pointer in disable or DPMS will fail (Jesse)
put register offsets in pll struct (Chris)
v3: Decouple enable/disable of PLLs from get/put.
v4: Track temporary PLL disabling during modeset
v5: Tidy PLL initialisation by only checking for num_pch_pll == 0 (Eugeni)
v6: Avoid mishandling allocation failure by embedding the small array of
PLLs into the device struct
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=44309
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org> (up to v2)
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> (v3+)
Reviewed-by: Eugeni Dodonov <eugeni.dodonov@intel.com>
Tested-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Reviewed-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
This originally started as a patch from Bernard as a way of simply
setting the VS scheduler. After submitting the RFC patch, we decided to
also modify the DS scheduler. To be most explicit, I've made the patch
explicitly set all scheduler modes, and included the defines for other
modes (in case someone feels frisky later).
The rest of the story gets a bit weird. The first version of the patch
showed an almost unbelievable performance improvement. Since rebasing my
branch it appears the performance improvement has gone, unfortunately.
But setting these bits seem to be the right thing to do given that the
docs describe corruption that can occur with the default settings.
In summary, I am seeing no more perf improvements (or regressions) in my
limited testing, but we believe this should be set to prevent rendering
corruption, therefore cc stable.
v1: Clear bit 4 also (Ken + Eugeni)
Do a full clear + set of the bits we want (Me).
Cc: Bernard Kilarski <bernard.r.kilarski@intel.com>
Cc: stable <stable@vger.kernel.org>
Reviewed-by (RFC): Kenneth Graunke <kenneth@whitecape.org>
Signed-off-by: Ben Widawsky <benjamin.widawsky@intel.com>
Reviewed-by: Eugeni Dodonov <eugeni.dodonov@intel.com>
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
The (2<<6) virtual memory space selector harks back to gen3 and is
mandatory given our use of GTT space for batchbuffers. On gen4+, use of
the GTT became mandatory and bit6 marked reserved. However the code must
now explicitly set (1<<7), which conveniently is also (2<<6).
To clarify the meaning for future readers, replace the open coded (2<<6)
with MI_BATCH_GTT.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
The purpose of this patch is to avoid zeroing the lower 12 reserved bits
of surface base address registers (framebuffer & sprite). There are bits
in that range that may occasionally be set by BIOS or by other components.
Signed-off-by: Armin Reese <armin.c.reese@intel.com>
Reviewed-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Those are used to program the WRPLL dividers correctly for each gives
frequency.
Signed-off-by: Eugeni Dodonov <eugeni.dodonov@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Our workaround list kindly lists that this new default value needs to
be updated in Bspec. Naturally, this did not happen.
Acked-by: Ben Widawsky <ben@bwidawsk.net>
Signed-Off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
According to Bsepc, this should be set by default, but isn't. See vo1c.4
"Render Engine Command Streamer", Section 1.1.14.3 "3D_CHICKEN3"
Bspec also says that we always need to set all mask bits.
v2: Add comment about the mask bits wtf.
Reviewed-by: Ben Widawsky <ben@bwidawsk.net>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
For some reason snb has 2 fields to set ppgtt cacheability. This one
here does not exist on gen7.
This might explain why ppgtt wasn't a win on snb like on ivb - not
enough pte caching.
v2: Fixup rebase fail.
Reviewed-by: Ben Widawsky <ben@bwidawsk.net>
Signed-Off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Bspec says that we need to set this: vol1c.3 "Blitter Command
Streamer", Section 1.1.2.1 "GAB_CTL_REG - GAB Unit Control Register".
We don't really rely on pagefaults, but who knows what this all
affects.
Reviewed-by: Ben Widawsky <ben@bwidawsk.net>
Signed-Off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Contrary to the other clock gating w/a in GEN6_UCGCTL1, this one is
actually documented in Bspec, vol1g "GT Interface Registers [SNB]",
Section 1.5.1 "UCGCTL1 - Unit Level Clock Gating Control 1".
Supposedly this can prevent hangs on the media ring.
Reviewed-by: Ben Widawsky <ben@bwidawsk.net>
Signed-Off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
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Merge tag 'v3.4-rc3' into drm-intel-next-queued
Backmerge Linux 3.4-rc3 into drm-intel-next to resolve a few things
that conflict/depend upon patches in -rc3:
- Second part of the Sandybridge workaround series - it changes some
of the same registers.
- Preparation for Chris Wilson's fencing cleanup - we need the fix
from -rc3 merged before we can move around all that code.
- Resolve the gmbus conflict - gmbus has been disabled in 3.4 again,
but should be enabled on all generations in 3.5.
Conflicts:
drivers/gpu/drm/i915/intel_i2c.c
Signed-Off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
RC6 residency should be in intervals of 1.28us, and the counter wraps.
Here is an example using awk to get the various RC6 and RC6+ residency
times in seconds, since boot.
cat /sys/kernel/debug/dri/0/i915_drpc_info | grep residency | awk -F':' -F' ' '{print $5 * 1.28 / 1000000}'
This is primarily for QA, but has other applications as well. An
upcoming patch to add interfaces should be more interesting to
application developers.
v2: move comment to the correct place
v3: display with %u instead of %d, for Ouping
CC: Ouping Zhang <ouping.zhang@intel.com>
Reviewed-by: Eugeni Dodonov <eugeni.dodonov@intel.com>
Signed-off-by: Ben Widawsky <benjamin.widawsky@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Daniel Vetter wrote
First pull request for 3.5-next, slightly large than usual because new
things kept coming in since the last pull for 3.4.
Highlights:
- first batch of hw enablement for vlv (Jesse et al) and hsw (Eugeni). pci
ids are not yet added, and there's still quite a few patches to merge
(mostly modesetting). To make QA easier I've decided to merge this stuff
in pieces.
- loads of cleanups and prep patches spurred by the above. Especially vlv
is a real frankenstein chip, but also hsw is stretching our driver's
code design. Expect more to come in this area for 3.5.
- more gmbus fixes, cleanups and improvements by Daniel Kurtz. Again,
there are more patches needed (and some already queued up), but I wanted
to split this a bit for better testing.
- pwrite/pread rework and retuning. This series has been in the works for
a few months already and a lot of i-g-t tests have been created for it.
Now it's finally ready to be merged. Note that one patch in this series
touches include/pagemap.h, that patch is acked-by akpm.
- reduce mappable pressure and relocation throughput improvements from
Chris.
- mmap offset exhaustion mitigation by Chris Wilson.
- a start at figuring out which codepaths in our messy dri1/ums+gem/kms
driver we actually need to support by bailing out of unsupported case.
The driver now refuses to load without kms on gen6+ and disallows a few
ioctls that userspace never used in certain cases. More of this will
definitely come.
- More decoupling of global gtt and ppgtt.
- Improved dual-link lvds detection by Takashi Iwai.
- Shut up the compiler + plus fix the fallout (Ben)
- Inverted panel brightness handling (mostly Acer manages to break things
in this way).
- Small fixlets and adjustements and some minor things to help debugging.
Regression-wise QA reported quite a few issues on ivb, but all of them
turned out to be hw stability issues which are already fixed in
drm-intel-fixes (QA runs the nightly regression tests on -next alone,
without -fixes automatically merged in). There's still one issue open on
snb, it looks like occlusion query writes are not quite as cache coherent
as we've expected. With some of the pwrite adjustements we can now
reliably hit this. Kernel workaround for it is in the works."
* 'drm-intel-next' of git://people.freedesktop.org/~danvet/drm-intel: (101 commits)
drm/i915: VCS is not the last ring
drm/i915: Add a dual link lvds quirk for MacBook Pro 8,2
drm/i915: make quirks more verbose
drm/i915: dump the DMA fetch addr register on pre-gen6
drm/i915/sdvo: Include YRPB as an additional TV output type
drm/i915: disallow gem init ioctl on ilk
drm/i915: refuse to load on gen6+ without kms
drm/i915: extract gt interrupt handler
drm/i915: use render gen to switch ring irq functions
drm/i915: rip out old HWSTAM missed irq WA for vlv
drm/i915: open code gen6+ ring irqs
drm/i915: ring irq cleanups
drm/i915: add SFUSE_STRAP registers for digital port detection
drm/i915: add WM_LINETIME registers
drm/i915: add WRPLL clocks
drm/i915: add LCPLL control registers
drm/i915: add SSC offsets for SBI access
drm/i915: add port clock selection support for HSW
drm/i915: add S PLL control
drm/i915: add PIXCLK_GATE register
...
Conflicts:
drivers/char/agp/intel-agp.h
drivers/char/agp/intel-gtt.c
drivers/gpu/drm/i915/i915_debugfs.c
According to an internal workaround master list, we need to set bit 5
of register 9400 to avoid issues with color blits.
Testing shows that this seems to fix the blitter hangs when fbc is
enabled on snb, thanks to Chris Wilson for figuring this out.
Tested-by: Chris Wilson <chris@chris-wilson.co.uk>
Tested-by: Michael "brot" Groh <michael.groh@minad.de>
Acked-by: Ben Widawsky <ben@bwidawsk.net>
Signed-Off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
It exists way back to gen2, bug got moved around on gen4 a bit.
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-Off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
- gen6 put/get only need one argument
rflags and gflags are always the same (see above explanation)
- remove a couple redundantly defined IRQs
- reordered some lines to make things go in descending order
Every ring has its own interrupts, enables, masks, and status bits that
are fed into the main interrupt enable/mask/status registers. At one
point in time it seemed like a good idea to make our functions support
the notion that each interrupt may have a different bit position in the
corresponding register (blitter parser error may be bit n in IMR, but
bit m in blitter IMR). It turned out though that the HW designers did us
a solid on Gen6+ and this unfortunate situation has been avoided. This
allows our interrupt code to be cleaned up a bit.
I jammed this into one commit because there should be no functional
change with this commit, and staging it into multiple commits was
unnecessarily artificial IMO.
CC: Chris Wilson <chris@chris-wilson.co.uk>
CC: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Ben Widawsky <benjamin.widawsky@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
[danvet:
- fixed up merged conflict with vlv changes.
- added GEN6 to GT blitter bit, we only use it on gen6+.
- added a comment to both ring irq bits and GT irq bits that on gen6+
these alias.
- added comment that GT_BSD_USER_INTERRUPT is ilk-only.
- I've got confused a bit that we still use GT_USER_INTERRUPT on ivb
for the render ring - but this goes back to ilk where we have only
gt interrupt bits and so we be equally confusing if changed.]
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
DDIA is detected via the DDI_BUF_CTL registers bit 0, but for DDIB, DDIC
and DDID we need to consult SFUSE_STRAP values.
Signed-off-by: Eugeni Dodonov <eugeni.dodonov@intel.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Watermark line time registers for display low power watermark.
v2: improve bit names as suggested by Chris Wilson
Signed-off-by: Eugeni Dodonov <eugeni.dodonov@intel.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
The WR PLL can drive the DDI ports at fixed frequencies for HDMI, DVI, DP
and FDI.
Signed-off-by: Eugeni Dodonov <eugeni.dodonov@intel.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Those are used to control the display core clock.
v2: change the enable bit setting, spotted by Rodrigo Vivi.
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Eugeni Dodonov <eugeni.dodonov@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Different registers are identified by their target id and offset. To
simplify their programming, they are called as <RegisterName><TargetId>.
For example, SSCCTL register accessed through SBI at target id 6 and
offset 0c is called SBI_SSCCTL6.
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@gmail.com>
Signed-off-by: Eugeni Dodonov <eugeni.dodonov@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Multiple clocks can drive different outputs.
v2: use the port enums to access individual ports
v1 Reviewed-by: Rodrigo Vivi <rodrigo.vivi@gmail.com>
Signed-off-by: Eugeni Dodonov <eugeni.dodonov@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
This PLL control can drive DDI ports at desired frequencies for
DisplayPort and FDI connections.
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@gmail.com>
Signed-off-by: Eugeni Dodonov <eugeni.dodonov@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Those are responsible for the Sideband Interface programming.
v2: rename SBI bits to better reflect their meaning
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Eugeni Dodonov <eugeni.dodonov@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Those registers are used to train DDI buffer translations for each link
type.
v2: access each port registers through the DDI_BUF_TRANS macro
Signed-off-by: Eugeni Dodonov <eugeni.dodonov@intel.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
There is one instance of those registers for each DDI port.
v2: access registers via the DDI_BUF_CTL() macro
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Eugeni Dodonov <eugeni.dodonov@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
There is one set of those registers for each port.
Signed-off-by: Eugeni Dodonov <eugeni.dodonov@intel.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
This is one set of those registers for each pipe.
v2: use port enum to access individual registers
Signed-off-by: Eugeni Dodonov <eugeni.dodonov@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
There is one set of such registers for each pipe (A/B/C/EDP).
v2: update to use DDI PORTS enum
v1 Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Eugeni Dodonov <eugeni.dodonov@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
There are 5 DDI ports on Haswell. Port A is always enabled, and is the one
connected to eDP, and Port E is the one that can be connected to the PCH
using FDI protocol. Ports B, C, D and E can be used for digital outputs.
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Eugeni Dodonov <eugeni.dodonov@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
This defines the registers used by different power wells.
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Eugeni Dodonov <eugeni.dodonov@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Quoting the BSpec from time immemorial:
PIPEACONF, bits 28:27: Frame Start Delay (Debug)
Used to delay the frame start signal that is sent to the display planes.
Care must be taken to insure that there are enough lines during VBLANK
to support this setting.
An instance of the BIOS leaving these bits set was found in the wild,
where it caused our modesetting to go all squiffy and skewiff.
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=47271
Reported-and-tested-by: Eva Wang <evawang@linpus.com>
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=43012
Reported-and-tested-by: Carl Richell <carl@system76.com>
Cc: stable@kernel.org
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
ValleyView has a new interrupt architecture; best to put it in a new set
of functions. Also make sure the ring mask functions handle ValleyView.
FIXME: fix flipping; need to enable interrupts and call prepare/finish
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
ValleyView handles force wake differently than previous chipsets, so add
a couple of new functions for it. But leave it disabled by default
until we test it (need a chip with the Punit enabled first).
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
HDMI register offsets are different in Valleyview. Add support for the
same.
v2: drop superfluous comments in HDMI init (Daniel)
Signed-off-by: Beeresh G <beeresh.g@intel.com>
Signed-off-by: Shobhit Kumar <shobhit.kumar@intel.com>
Reviewed-by: Vijay Purushothaman <vijay.a.purushothaman@intel.com>
Reviewed-by: Jesse Barnes <jesse.barnes@intel.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Set required clock gating and chicken bits on VLV.
v2: set PIXEL_SUBSPAN_COLLECT_OPT_DISABLE too (Ben)
move function below ivb version to pretend to be consistent (Ben)
Reviewed-by: Ben Widawsky <ben@bwidawsk.net>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
ValleyView puts some display related registers like the PLL controls and
dividers behind the DPIO bus. Add simple indirect register access
routines to get to those registers.
v2: move new wait_for macro to intel_drv.h (Ben)
fix DPIO_PKT double write (Ben)
add debugfs file
Reviewed-by: Ben Widawsky <ben@bwidawsk.net>
Reviewed-by: Eugeni Dodonov <eugeni.dodonov@intel.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Add support for ValleyView watermark handling.
v2: remove unused reg & bit definitions (Ben)
Acked-by: Ben Widawsky <ben@bwidawsk.net>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
There is no GMBUS "disabled" port 0, nor "reserved" port 7.
For the other 6 ports there is a fixed 1:1 mapping between pin pairs and
gmbus ports, which means every real gmbus port has a gpio pin.
Given these realizations, clean up gmbus initialization.
Tested on Sandybridge (gen 6, PCH == CougarPoint) hardware.
Signed-off-by: Daniel Kurtz <djkurtz@chromium.org>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
According to i915 documentation [1], "Port D" (DP/HDMI Port D) is
actually gmbus pin pair 6 (gmbus0.2:0 == 110b GPIOF), not 7 (111b).
Pin pair 7 is a reserved pair.
[1] Documentation for [DevSNB+] and [DevIBX], as found on
http://intellinuxgraphics.org:
[DevSNB+]:
http://intellinuxgraphics.org/documentation/SNB/IHD_OS_Vol3_Part3.pdf
Section 2.2.2 lists the 6 gmbus ports (gpio pin pairs):
[ 5: HDMI/DPD, 4: HDMIB, 3: HDMI/DPC, 2: LVDS, 1: SSC, 0: VGA ]
2.2.2.1 lists the GPIO registers to control these 6 ports.
2.2.3.1 lists the mapping between 5 of these gmbus ports and the 3
Pin_Pair_Select bits (of the GMBUS0 register). This table is missing
HDMIB (port 101).
[DevIBX]: http://intellinuxgraphics.org/IHD_OS_Vol3_Part3r2.pdf
Section 2.2.2 lists the same 6 gmbus ports plus two 'reserved' gpio
ports.
2.2.2.1 lists 8 GPIO registers... however, it says the size of the
block is 6x32, which implies that those 2 reserved GPIO registers
(GPIO_6 & GPIO_7) don't actually exist (or are irrelevant).
2.2.3.1 lists the mapping between the 6 named gmbus ports and the 3
Pin_Pair_Select bits (of the GMBUS0 register). This table has HDMIB.
Note: the "reserved" and "disabled" pairs do not actually map to a
physical pair of pins, nor GPIO regs and shouldn't be initialized or used.
Fixing this is left for a later patch.
This bug had not been noticed earlier for two reasons:
1) Until recently, "gmbus" mode was disabled - all transfers actually
used "bit-bang" mode on GPIO port 5 (the "HDMI/DPD CTLDATA/CLK"
pair), at register 0x5024 (defined as GPIOF i915_reg.h).
Since this is the correct pair of pins for HDMI1, transfers succeed.
2) Even if gmbus mode is re-enabled, the first attempted transaction
will fail because it tries to use the wrong ("Reserved") pin pair.
However, the driver immediately falls back again to the bit-bang
method, which correctly uses GPIOF, so again, transfers succeed.
However, if gmbus mode is re-enabled and the GPIO fall-back mode is
disabled, then reading an attached monitor's EDID fail.
Signed-off-by: Daniel Kurtz <djkurtz@chromium.org>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
