Hi,
On 11/1/23 10:32, Andy Shevchenko wrote:
> On Tue, Oct 31, 2023 at 10:15:52PM +0100, Hans de Goede wrote:
>> On 10/31/23 17:07, Hans de Goede wrote:
>>> On 10/24/23 18:11, Andy Shevchenko wrote:
>>>> On Tue, Oct 24, 2023 at 06:57:38PM +0300, Andy Shevchenko wrote:
>
> ...
>
>>> As for the CHT support, I have not added that to my tree yet, I would
>>> prefer to directly test the correct/fixed patch.
>>
>> And I hit the "jackpot" on the first device I tried and the code needed
>> some fixing to actually work, so here is something to fold into v3 to
>> fix things:
>
> Thanks!
>
> But let me first send current v3 as it quite differs to v2 in the sense
> of how I do instantiate GPIO lookup tables.
The problem is there already is a GPIO lookup table registered for
the "0000:00:02.0" device by intel_dsi_vbt_gpio_init() and there can
be only be one GPIO lookup table per device. So no matter how you
instantiate GPIO lookup tables it will not work.
The solution that I chose is to not instantiate a GPIO lookup table
at all and instead to extend the existing table with an extra entry.
Although thinking more about it I must admit that this is racy.
So a better idea would be to unregister the GPIO lookup
table registered by intel_dsi_vbt_gpio_init() after getting
the GPIOs there, that would allow instantiating a new one
from soc_exec_opaque_gpio() as it currently does and that
would be race free.
> Meanwhile I will look into the change you sent (and hopefully we can
> incorporate something in v3 for v4).
Ok, lets go with your v3.
I'll prepare a patch to move the unregistering of the existing
conflicting GPIO lookup from intel_dsi_vbt_gpio_cleanup()
to the end of intel_dsi_vbt_gpio_init() to avoid the conflict
we have there.
Note you still need the first part of my patch which is
an unrelated bugfix:
--- a/drivers/gpu/drm/i915/display/intel_dsi_vbt.c
+++ b/drivers/gpu/drm/i915/display/intel_dsi_vbt.c
@@ -219,8 +219,7 @@ static void soc_exec_gpio(struct intel_connector *connector, const char *con_id,
} else {
gpio_desc = devm_gpiod_get_index(dev_priv->drm.dev,
con_id, gpio_index,
- value ? GPIOD_OUT_LOW :
- GPIOD_OUT_HIGH);
+ value ? GPIOD_OUT_HIGH : GPIOD_OUT_LOW);
if (IS_ERR(gpio_desc)) {
drm_err(&dev_priv->drm,
"GPIO index %u request failed (%pe)\n",
Regards,
Hans
