linux-toradex.git/drivers/gpu/drm/i2c/adv7511.c, branch v4.4.92

drm/bridge: adv7511: Re-write the i2c address before EDID probing

2017-09-13T21:09:46+00:00

commit 3587c856675c45809010c2cee5b21096f6e8e938 upstream.

I've found that by just turning the chip on and off via the
POWER_DOWN register, I end up getting i2c_transfer errors on
HiKey.

Investigating further, it turns out that some of the register
state in hardware is getting lost, as the device registers are
reset when the chip is powered down.

Thus this patch simply re-writes the i2c address to the
ADV7511_REG_EDID_I2C_ADDR register to ensure its properly set
before we try to read the EDID data.

Cc: David Airlie 
Cc: Archit Taneja 
Cc: Wolfram Sang 
Cc: Lars-Peter Clausen 
Cc: Laurent Pinchart 
Cc: dri-devel@lists.freedesktop.org
Reviewed-by: Laurent Pinchart 
Tested-by: Laurent Pinchart 
Signed-off-by: John Stultz 
Signed-off-by: Archit Taneja 
Link: http://patchwork.freedesktop.org/patch/msgid/1484614372-15342-7-git-send-email-john.stultz@linaro.org
Signed-off-by: Thong Ho 
Signed-off-by: Nhan Nguyen 
Signed-off-by: Greg Kroah-Hartman

drm/bridge: adv7511: Switch to using drm_kms_helper_hotplug_event()

2017-09-13T21:09:46+00:00

commit 6d5104c5a6b56385426e15047050584794bb6254 upstream.

In chasing down a previous issue with EDID probing from calling
drm_helper_hpd_irq_event() from irq context, Laurent noticed
that the DRM documentation suggests that
drm_kms_helper_hotplug_event() should be used instead.

Thus this patch replaces drm_helper_hpd_irq_event() with
drm_kms_helper_hotplug_event(), which requires we update the
connector.status entry and only call _hotplug_event() when the
status changes.

Cc: David Airlie 
Cc: Archit Taneja 
Cc: Wolfram Sang 
Cc: Lars-Peter Clausen 
Cc: Laurent Pinchart 
Cc: dri-devel@lists.freedesktop.org
Reviewed-by: Laurent Pinchart 
Tested-by: Laurent Pinchart 
Signed-off-by: John Stultz 
Signed-off-by: Archit Taneja 
Link: http://patchwork.freedesktop.org/patch/msgid/1484614372-15342-3-git-send-email-john.stultz@linaro.org
Signed-off-by: Thong Ho 
Signed-off-by: Nhan Nguyen 
Signed-off-by: Greg Kroah-Hartman

drm/bridge: adv7511: Use work_struct to defer hotplug handing to out of irq context

2017-09-13T21:09:46+00:00

commit 518cb7057a59b9441336d2e88a396d52b6ab0cce upstream.

I was recently seeing issues with EDID probing, where
the logic to wait for the EDID read bit to be set by the
IRQ wasn't happening and the code would time out and fail.

Digging deeper, I found this was due to the fact that
IRQs were disabled as we were running in IRQ context from
the HPD signal.

Thus this patch changes the logic to handle the HPD signal
via a work_struct so we can be out of irq context.

With this patch, the EDID probing on hotplug does not time
out.

Cc: David Airlie 
Cc: Archit Taneja 
Cc: Wolfram Sang 
Cc: Lars-Peter Clausen 
Cc: Laurent Pinchart 
Cc: dri-devel@lists.freedesktop.org
Reviewed-by: Laurent Pinchart 
Tested-by: Laurent Pinchart 
Signed-off-by: John Stultz 
Signed-off-by: Archit Taneja 
Link: http://patchwork.freedesktop.org/patch/msgid/1484614372-15342-2-git-send-email-john.stultz@linaro.org
Signed-off-by: Thong Ho 
Signed-off-by: Nhan Nguyen 
Signed-off-by: Greg Kroah-Hartman

drm/bridge: adv7511: Fix mutex deadlock when interrupts are disabled

2017-09-13T21:09:45+00:00

commit f0bfcc22d9822947b0ad3095e8363eab5261864c upstream.

When the adv7511 i2c client doesn't have an interrupt line, we observe a
deadlock on caused by trying to lock drm device's mode_config.mutex twice
in the same context.

Here is the sequence that causes it:

ioctl DRM_IOCTL_MODE_GETCONNECTOR from userspace
  drm_mode_getconnector (acquires mode_config mutex)
    connector->fill_modes()
    drm_helper_probe_single_connector_modes
      connector_funcs->get_modes
	adv7511_encoder_get_modes
	  adv7511_get_edid_block
	    adv7511_irq_process
	      drm_helper_hpd_irq_event (acquires mode_config mutex again)

In adv7511_irq_process, don't call drm_helper_hpd_irq_event when not
called from the interrupt handler. It doesn't serve any purpose there
anyway.

Signed-off-by: Archit Taneja 
Signed-off-by: Thong Ho 
Signed-off-by: Nhan Nguyen 
Signed-off-by: Greg Kroah-Hartman

drm: adv7511: really enable interrupts for EDID detection

2017-09-13T21:09:45+00:00

commit d0be8584b01160eb6f49e77f8e9c1da286bb4ffb upstream.

The interrupts for EDID_READY or DDC_ERROR were never enabled in this
driver, so reading EDID always timed out when chip was powered down and
interrupts were used. Fix this and also remove clearing the interrupt
flags, they are cleared in POWER_DOWN mode anyhow (unlike the interrupt
enable flags) according to docs and my tests.

Signed-off-by: Wolfram Sang 
Tested-by: Archit Taneja 
Signed-off-by: Thong Ho 
Signed-off-by: Nhan Nguyen 
Signed-off-by: Greg Kroah-Hartman

regmap: Use reg_sequence for multi_reg_write / register_patch

2015-07-16T21:02:55+00:00

Separate the functionality using sequences of register writes from the
functions that take register defaults. This change renames the arguments
in order to support the extension of reg_sequence to take an optional
delay to be applied after any given register in a sequence is written.
This avoids adding an int to all register defaults, which could
substantially increase memory usage for regmaps with large default tables.

This also updates all the clients of multi_reg_write/register_patch.

Signed-off-by: Nariman Poushin 
Signed-off-by: Mark Brown

drm: adv7511: Fix crash in IRQ handler when no encoder is associated

2015-05-25T12:34:00+00:00

The ADV7511 is probed before its slave encoder init function associates
it with an encoder. This creates a time window during which hot plug
detection interrupts can occur with an encoder, resulting in a crash in
the IRQ handler.

Fix this by ignoring hot plug detection IRQs when no encoder is
associated yet.

Signed-off-by: Laurent Pinchart 
Acked-by: Lars-Peter Clausen

drm: adv7511: Refactor power management

2015-03-19T10:28:55+00:00

Remove the internal dependency on DPMS mode for power management by
using a by a powered state boolean instead, and use the new power off
handler at probe time. This ensure that the regmap cache is properly
marked as dirty when the device is probed, and the registers properly
synced during the first power up.

As a side effect this removes the initialization of current_edid_segment
at probe time, as the field will be initialized when the device is
powered on, at the latest right before reading EDID data.

Signed-off-by: Laurent Pinchart 
Tested-by: Christian Kohn 
Tested-by: Lars-Peter Clausen 
Acked-by: Lars-Peter Clausen

drm: adv7511: Fix nested sleep when reading EDID

2015-03-19T10:28:55+00:00

The EDID read code waits for the read completion interrupt to occur
using wait_event_interruptible(). The condition passed to the macro
reads I2C registers. This results in sleeping with the task state set
to TASK_INTERRUPTIBLE, triggering a WARN_ON() introduced in commit
8eb23b9f35aae ("sched: Debug nested sleeps").

Fix this by reworking the EDID read code. Instead of checking whether
the read is complete through I2C reads, handle the interrupt registers
in the interrupt handler and update a new edid_read flag accordingly. As
a side effect both the IRQ and polling code paths now process the
interrupt sources through the same code path, simplifying the code.

Cc: stable@vger.kernel.org
Signed-off-by: Laurent Pinchart

drm: adv7511: Fix DDC error interrupt handling

2015-03-19T10:28:55+00:00

The DDC error interrupt bit is located in REG_INT1, not REG_INT0. Update
both the interrupt wait code and the interrupt sources reset code
accordingly.

Cc: stable@vger.kernel.org
Signed-off-by: Laurent Pinchart