On 11/29/2016 10:34 AM, John Stultz wrote:
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 seems some of the register state
in the regmap cache is somehow getting lost. Using the logic
in __adv7511_power_on/off() which syncs and dirtys the cache
avoids this issue.
Thus this patch changes the EDID probing logic so that we
re-use the __adv7511_power_on/off() calls.
Cc: David Airlie <[email protected]>
Cc: Archit Taneja <[email protected]>
Cc: Wolfram Sang <[email protected]>
Cc: Lars-Peter Clausen <[email protected]>
Cc: Laurent Pinchart <[email protected]>
Cc: [email protected]
Signed-off-by: John Stultz <[email protected]>
---
v2: Split into two patches to make the change more clear.
Also provided more rational as to why the change is
important.
drivers/gpu/drm/bridge/adv7511/adv7511_drv.c | 17 +++--------------
1 file changed, 3 insertions(+), 14 deletions(-)
diff --git a/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c
b/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c
index 1948968..487b33d 100644
--- a/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c
+++ b/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c
@@ -559,24 +559,13 @@ static int adv7511_get_modes(struct adv7511 *adv7511,
unsigned int count;
/* Reading the EDID only works if the device is powered */
- if (!adv7511->powered) {
- regmap_update_bits(adv7511->regmap, ADV7511_REG_POWER,
- ADV7511_POWER_POWER_DOWN, 0);
- if (adv7511->i2c_main->irq) {
- regmap_write(adv7511->regmap, ADV7511_REG_INT_ENABLE(0),
- ADV7511_INT0_EDID_READY);
- regmap_write(adv7511->regmap, ADV7511_REG_INT_ENABLE(1),
- ADV7511_INT1_DDC_ERROR);
- }
- adv7511->current_edid_segment = -1;
- }
+ if (!adv7511->powered)
+ __adv7511_power_on(adv7511);
In terms of changes in terms of register configurations, replacing with
__adv7511_power_on() here would add a register write to ADV7511_REG_POWER2
as discussed before.
Also, after the patch that enables HPD, we'd also be adding the ADV7511_INT0_HPD
bit in ADV7511_REG_INT_ENABLE(0).
I am not entirely sure about what effect adding POWER2 would have. If we don't
see any negative effects because of it, I think we should be fine.
The extra HPD bit in INT_ENABLE(0) shouldn't be a problem, though. In fact, it
prevents the HPD mask from being cleared after we get_modes is called, which may
have resulted in us missing out on HPD interrupts.
Thanks,
Archit
edid = drm_do_get_edid(connector, adv7511_get_edid_block, adv7511);
if (!adv7511->powered)
- regmap_update_bits(adv7511->regmap, ADV7511_REG_POWER,
- ADV7511_POWER_POWER_DOWN,
- ADV7511_POWER_POWER_DOWN);
+ __adv7511_power_off(adv7511);
kfree(adv7511->edid);
adv7511->edid = edid;
--
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