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 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
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;