drm/i915/i2c: Track users of GMBUS force-bit
This fixes a regression for SDVO from
commit fbfcc4f3a0cf8bbde87646b74241faa8e37426bf
Author: Jani Nikula <jani.nikula@intel.com>
Date: Mon Oct 22 16:12:18 2012 +0300
drm/i915/sdvo: restore i2c adapter config on intel_sdvo_init() failures
As SDVOB and SDVOC are multiplexed on the same pin, if a chipset does
not have the second SDVO encoder, it will then remove the force-bit
setting on the common i2c adapter during teardown. All subsequent
attempts of trying to use GMBUS with SDVOB then fail.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Jani Nikula <jani.nikula@intel.com>
Cc: Mika Kuoppala <mika.kuoppala@intel.com>
[danvet: fixup inversion in the debug printout, noticed by Jani
Nikulai.]
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index f316916..db6d71c 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -390,7 +390,7 @@
struct intel_gmbus {
struct i2c_adapter adapter;
- bool force_bit;
+ u32 force_bit;
u32 reg0;
u32 gpio_reg;
struct i2c_algo_bit_data bit_algo;
diff --git a/drivers/gpu/drm/i915/intel_i2c.c b/drivers/gpu/drm/i915/intel_i2c.c
index c2c6dbc..3ef5af1 100644
--- a/drivers/gpu/drm/i915/intel_i2c.c
+++ b/drivers/gpu/drm/i915/intel_i2c.c
@@ -432,7 +432,7 @@
I915_WRITE(GMBUS0 + reg_offset, 0);
/* Hardware may not support GMBUS over these pins? Try GPIO bitbanging instead. */
- bus->force_bit = true;
+ bus->force_bit = 1;
ret = i2c_bit_algo.master_xfer(adapter, msgs, num);
out:
@@ -491,7 +491,7 @@
/* gmbus seems to be broken on i830 */
if (IS_I830(dev))
- bus->force_bit = true;
+ bus->force_bit = 1;
intel_gpio_setup(bus, port);
@@ -532,7 +532,10 @@
{
struct intel_gmbus *bus = to_intel_gmbus(adapter);
- bus->force_bit = force_bit;
+ bus->force_bit += force_bit ? 1 : -1;
+ DRM_DEBUG_KMS("%sabling bit-banging on %s. force bit now %d\n",
+ force_bit ? "en" : "dis", adapter->name,
+ bus->force_bit);
}
void intel_teardown_gmbus(struct drm_device *dev)