Hi Dmitry,
> On 31/03/2022 08:53, Sankeerth Billakanti (QUIC) wrote:
> > Hi Dmitry,
> >
> >> On Wed, 30 Mar 2022 at 19:03, Sankeerth Billakanti
> >> <quic_sbillaka@xxxxxxxxxxx> wrote:
> >>>
> >>> The interrupt register will still reflect the connect and disconnect
> >>> interrupt status without generating an actual HW interrupt.
> >>> The controller driver should not handle those masked interrupts.
> >>>
> >>> Signed-off-by: Sankeerth Billakanti <quic_sbillaka@xxxxxxxxxxx>
> >>> ---
> >>> drivers/gpu/drm/msm/dp/dp_catalog.c | 5 +++--
> >>> 1 file changed, 3 insertions(+), 2 deletions(-)
> >>>
> >>> diff --git a/drivers/gpu/drm/msm/dp/dp_catalog.c
> >>> b/drivers/gpu/drm/msm/dp/dp_catalog.c
> >>> index 3c16f95..1809ce2 100644
> >>> --- a/drivers/gpu/drm/msm/dp/dp_catalog.c
> >>> +++ b/drivers/gpu/drm/msm/dp/dp_catalog.c
> >>> @@ -608,13 +608,14 @@ u32 dp_catalog_hpd_get_intr_status(struct
> >>> dp_catalog *dp_catalog) {
> >>> struct dp_catalog_private *catalog = container_of(dp_catalog,
> >>> struct dp_catalog_private, dp_catalog);
> >>> - int isr = 0;
> >>> + int isr, mask;
> >>>
> >>> isr = dp_read_aux(catalog, REG_DP_DP_HPD_INT_STATUS);
> >>> dp_write_aux(catalog, REG_DP_DP_HPD_INT_ACK,
> >>> (isr & DP_DP_HPD_INT_MASK));
> >>> + mask = dp_read_aux(catalog, REG_DP_DP_HPD_INT_MASK);
> >>>
> >>> - return isr;
> >>> + return isr & (DP_DP_HPD_STATE_STATUS_MASK | mask);
> >>
> >> I suspect that the logic is inverted here. Shouldn't it be:
> >>
> >> return isr & DP_DP_HPD_STATE_STATUS_MASK & mask;
> >>
> >> ?
> >>
> >
> > The value of DP_DP_HPD_STATE_STATUS_MASK is 0xE0000000 and the
> value
> > of the read interrupt mask variable could be is 0xF.
> >
> > The mask value is indicated via the register, REG_DP_DP_HPD_INT_MASK,
> bits 3:0.
> > The HPD status is indicated via a different read-only register
> REG_DP_DP_HPD_INT_STATUS, bits 31:29.
>
> I see. Maybe the following expression would be better?
>
> return isr & (mask & ~DP_DP_HPD_INT_MASK);
>
I believe the confusion occurred because the DP_DP_HPD_STATE_STATUS_CONNECTED and others were defined under the same register definition as REG_DP_DP_HPD_INT_MASK
I will rearrange the definitions below.
#define REG_DP_DP_HPD_INT_MASK (0x0000000C)
#define DP_DP_HPD_PLUG_INT_MASK (0x00000001)
#define DP_DP_IRQ_HPD_INT_MASK (0x00000002)
#define DP_DP_HPD_REPLUG_INT_MASK (0x00000004)
#define DP_DP_HPD_UNPLUG_INT_MASK (0x00000008)
#define DP_DP_HPD_INT_MASK (DP_DP_HPD_PLUG_INT_MASK | \
DP_DP_IRQ_HPD_INT_MASK | \
DP_DP_HPD_REPLUG_INT_MASK | \
DP_DP_HPD_UNPLUG_INT_MASK)
Below are status bits from register REG_DP_DP_HPD_INT_STATUS
#define DP_DP_HPD_STATE_STATUS_CONNECTED (0x40000000)
#define DP_DP_HPD_STATE_STATUS_PENDING (0x20000000)
#define DP_DP_HPD_STATE_STATUS_DISCONNECTED (0x00000000)
#define DP_DP_HPD_STATE_STATUS_MASK (0xE0000000)
DP_DP_HPD_INT_MASK is 0xF and scope of mask variable is also 0xF (bits 3:0), mask & ~DP_DP_HPD_INT_MASK is 0 always.
For DP, we want to enable all interrupts.
So the programmed mask value is 0xF. We want to return 0x40000001 for connect and 8 for disconnect
For eDP, we want to disable the connect and disconnect interrupts. So, the mask will be 0x6 (i.e. DP_DP_IRQ_HPD_INT_MASK | DP_DP_HPD_REPLUG_INT_MASK)
We want to return 0x40000000 (or 0x20000000 based on hpd line status) and 0 for eDP connect and disconnect respectively.
> >
> > isr & DP_DP_HPD_STATE_STATUS_MASK & mask, will return 0 always.
> >
> >>> }
> >>>
> >>> int dp_catalog_ctrl_get_interrupt(struct dp_catalog *dp_catalog)
> >>> --
> >>> 2.7.4
> >>>
> >>
> >>
> >> --
> >> With best wishes
> >> Dmitry
> >
> > Thank you,
> > Sankeerth
>
>
> --
> With best wishes
> Dmitry
Thank you,
Sankeerth
