Hi John,
Thank you for the patch.
On Tuesday 03 Jan 2017 11:41:42 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.
regcache_sync() is quite costly as it will write a bunch of registers.
Wouldn't it be more efficient to only write the registers that are needed for
EDID access ?
> Cc: David Airlie <airl...@linux.ie>
> Cc: Archit Taneja <arch...@codeaurora.org>
> Cc: Wolfram Sang <wsa+rene...@sang-engineering.com>
> Cc: Lars-Peter Clausen <l...@metafoo.de>
> Cc: Laurent Pinchart <laurent.pinch...@ideasonboard.com>
> Cc: dri-devel@lists.freedesktop.org
> Signed-off-by: John Stultz <john.stu...@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;
--
Regards,
Laurent Pinchart
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