[PATCH v9 10/18] drm: bridge: samsung-dsim: Init exynos host for first DSI transfer

[Marek Szyprowski]

On 12.12.2022 09:32, Jagan Teki wrote:
> On Mon, Dec 12, 2022 at 1:56 PM Marek Szyprowski
> <m.szyprowski at samsung.com> wrote:
>> Hi Jagan,
>>
>> On 09.12.2022 16:23, Jagan Teki wrote:
>>> The existing drm panels and bridges in Exynos required host
>>> initialization during the first DSI command transfer even though
>>> the initialization was done before.
>>>
>>> This host reinitialization is handled via DSIM_STATE_REINITIALIZED
>>> flag and triggers from host transfer.
>>>
>>> Do this exclusively for Exynos.
>>>
>>> Initial logic is derived from Marek Szyprowski changes.
>>>
>>> Signed-off-by: Marek Szyprowski <m.szyprowski at samsung.com>
>>> Signed-off-by: Jagan Teki <jagan at amarulasolutions.com>
>>> ---
>>> Changes from v9:
>>> - derived from v8
>>> - added comments
>>>
>>>    drivers/gpu/drm/bridge/samsung-dsim.c | 15 ++++++++++++++-
>>>    include/drm/bridge/samsung-dsim.h     |  5 +++--
>>>    2 files changed, 17 insertions(+), 3 deletions(-)
>> The following chunk is missing compared to v8:
>>
>> diff --git a/drivers/gpu/drm/bridge/samsung-dsim.c
>> b/drivers/gpu/drm/bridge/samsung-dsim.c
>> index 6e9ad955ebd3..6a9403cb92ae 100644
>> --- a/drivers/gpu/drm/bridge/samsung-dsim.c
>> +++ b/drivers/gpu/drm/bridge/samsung-dsim.c
>> @@ -1315,7 +1315,9 @@ static int samsung_dsim_init(struct samsung_dsim
>> *dsi, unsigned int flag)
>>                   return 0;
>>
>>           samsung_dsim_reset(dsi);
>> -       samsung_dsim_enable_irq(dsi);
>> +
>> +       if (!(dsi->state & DSIM_STATE_INITIALIZED))
>> +               samsung_dsim_enable_irq(dsi);
> Is this really required? does it make sure that the IRQ does not enable twice?

That's what that check does. Without the 'if (!(dsi->state & 
DSIM_STATE_INITIALIZED))' check, the irqs will be enabled twice (first 
from pre_enable, then from the first transfer), what leads to a warning 
from irq core.

Best regards
-- 
Marek Szyprowski, PhD
Samsung R&D Institute Poland