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| Started by | John Stultz <john.stultz@linaro.org> |
|---|---|
| First post | 2016-11-29 06:10 +0100 |
| Last post | 2016-11-30 05:50 +0100 |
| Articles | 2 — 2 participants |
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[RFC][PATCH 5/5 v2] drm/bridge: adv7511: Reuse __adv7511_power_on/off() when probing EDID John Stultz <john.stultz@linaro.org> - 2016-11-29 06:10 +0100
Re: [RFC][PATCH 5/5 v2] drm/bridge: adv7511: Reuse __adv7511_power_on/off() when probing EDID Archit Taneja <architt@codeaurora.org> - 2016-11-30 05:50 +0100
| From | John Stultz <john.stultz@linaro.org> |
|---|---|
| Date | 2016-11-29 06:10 +0100 |
| Subject | [RFC][PATCH 5/5 v2] drm/bridge: adv7511: Reuse __adv7511_power_on/off() when probing EDID |
| Message-ID | <sIIQ1-3R4-1@gated-at.bofh.it> |
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);
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;
--
2.7.4
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| From | Archit Taneja <architt@codeaurora.org> |
|---|---|
| Date | 2016-11-30 05:50 +0100 |
| Subject | Re: [RFC][PATCH 5/5 v2] drm/bridge: adv7511: Reuse __adv7511_power_on/off() when probing EDID |
| Message-ID | <sJ50d-1gP-7@gated-at.bofh.it> |
| In reply to | #1531895 |
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;
>
--
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum,
a Linux Foundation Collaborative Project
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