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 airlied@linux.ie Cc: Archit Taneja architt@codeaurora.org Cc: Wolfram Sang wsa+renesas@sang-engineering.com Cc: Lars-Peter Clausen lars@metafoo.de Cc: Laurent Pinchart laurent.pinchart@ideasonboard.com Cc: dri-devel@lists.freedesktop.org Signed-off-by: John Stultz john.stultz@linaro.org --- 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 dbdb71c..24573e0 100644 --- a/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c +++ b/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c @@ -572,24 +572,13 @@ 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);
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;