| Message ID | 1480395884-5471-6-git-send-email-john.stultz@linaro.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
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; >
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); 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;
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(-)