[PATCH resend] drm/i915/bios: Apply vlv_fixup_mipi_sequences() to v2 mipi-sequences too

[Hans de Goede]

Hi Ville,

On 4-Jul-25 12:31 PM, Ville Syrjälä wrote:
> On Thu, Jul 03, 2025 at 04:38:24PM +0200, Hans de Goede wrote:
>> From: Hans de Goede <hdegoede at redhat.com>
>>
>> It turns out that the fixup from vlv_fixup_mipi_sequences() is necessary
>> for some DSI panel's with version 2 mipi-sequences too.
>>
>> Specifically the Acer Iconia One 8 A1-840 (not to be confused with the
>> A1-840FHD which is different) has the following sequences:
>>
>> BDB block 53 (1284 bytes) - MIPI sequence block:
>> 	Sequence block version v2
>> 	Panel 0 *
>>
>> Sequence 2 - MIPI_SEQ_INIT_OTP
>> 	GPIO index 9, source 0, set 0 (0x00)
>> 	Delay: 50000 us
>> 	GPIO index 9, source 0, set 1 (0x01)
>> 	Delay: 6000 us
>> 	GPIO index 9, source 0, set 0 (0x00)
>> 	Delay: 6000 us
>> 	GPIO index 9, source 0, set 1 (0x01)
>> 	Delay: 25000 us
>> 	Send DCS: Port A, VC 0, LP, Type 39, Length 5, Data ff aa 55 a5 80
>> 	Send DCS: Port A, VC 0, LP, Type 39, Length 3, Data 6f 11 00
>> 	...
>> 	Send DCS: Port A, VC 0, LP, Type 05, Length 1, Data 29
>> 	Delay: 120000 us
>>
>> Sequence 4 - MIPI_SEQ_DISPLAY_OFF
>> 	Send DCS: Port A, VC 0, LP, Type 05, Length 1, Data 28
>> 	Delay: 105000 us
>> 	Send DCS: Port A, VC 0, LP, Type 05, Length 2, Data 10 00
>> 	Delay: 10000 us
>>
>> Sequence 5 - MIPI_SEQ_ASSERT_RESET
>> 	Delay: 10000 us
>> 	GPIO index 9, source 0, set 0 (0x00)
>>
>> Notice how there is no MIPI_SEQ_DEASSERT_RESET, instead the deassert
>> is done at the beginning of MIPI_SEQ_INIT_OTP, which is exactly what
>> the fixup from vlv_fixup_mipi_sequences() fixes up.
>>
>> Extend it to also apply to v2 sequences, this fixes the panel not working
>> on the Acer Iconia One 8 A1-840.
> 
> Do we have the full VBT for this machine already in some bug? If not,
> please file a new issue with the VBT attached for posterity.

I've filed: https://gitlab.freedesktop.org/drm/i915/kernel/-/issues/14605
with the VBT attached and I'll add a Closes: tag pointing to that
to the patch while applying it to drm-intel-fixes.

Regards,

Hans



> 
>>
>> Signed-off-by: Hans de Goede <hdegoede at redhat.com>
>> ---
>>  drivers/gpu/drm/i915/display/intel_bios.c | 8 ++++----
>>  1 file changed, 4 insertions(+), 4 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/i915/display/intel_bios.c b/drivers/gpu/drm/i915/display/intel_bios.c
>> index ba7b8938b17c..166ee11831ab 100644
>> --- a/drivers/gpu/drm/i915/display/intel_bios.c
>> +++ b/drivers/gpu/drm/i915/display/intel_bios.c
>> @@ -1938,7 +1938,7 @@ static int get_init_otp_deassert_fragment_len(struct intel_display *display,
>>  	int index, len;
>>  
>>  	if (drm_WARN_ON(display->drm,
>> -			!data || panel->vbt.dsi.seq_version != 1))
>> +			!data || panel->vbt.dsi.seq_version >= 3))
>>  		return 0;
>>  
>>  	/* index = 1 to skip sequence byte */
>> @@ -1961,7 +1961,7 @@ static int get_init_otp_deassert_fragment_len(struct intel_display *display,
>>  }
>>  
>>  /*
>> - * Some v1 VBT MIPI sequences do the deassert in the init OTP sequence.
>> + * Some v1/v2 VBT MIPI sequences do the deassert in the init OTP sequence.
>>   * The deassert must be done before calling intel_dsi_device_ready, so for
>>   * these devices we split the init OTP sequence into a deassert sequence and
>>   * the actual init OTP part.
>> @@ -1972,9 +1972,9 @@ static void vlv_fixup_mipi_sequences(struct intel_display *display,
>>  	u8 *init_otp;
>>  	int len;
>>  
>> -	/* Limit this to v1 vid-mode sequences */
>> +	/* Limit this to v1/v2 vid-mode sequences */
>>  	if (panel->vbt.dsi.config->is_cmd_mode ||
>> -	    panel->vbt.dsi.seq_version != 1)
>> +	    panel->vbt.dsi.seq_version >= 3)
>>  		return;
>>  
>>  	/* Only do this if there are otp and assert seqs and no deassert seq */
>> -- 
>> 2.49.0
>