drm: xlnx: zynqmp_dpsub: Clear status register ASAP

Clear status register as soon as we read it.

Addressing comments from
https://lore.kernel.org/dri-devel/beb551c7-bb7e-4cd0-b166-e9aad90c4620@ideasonboard.com/

Signed-off-by: Anatoliy Klymenko <anatoliy.klymenko@amd.com>
Reviewed-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240124025402.373620-4-anatoliy.klymenko@amd.com

diff --git a/drivers/gpu/drm/xlnx/zynqmp_dp.c b/drivers/gpu/drm/xlnx/zynqmp_dp.c
index d60b7431603ff00bc84d63723a00e67e6701a843..5a3335e1fffada3fa62ad8850120174bd40a23b4 100644 (file)
--- a/drivers/gpu/drm/xlnx/zynqmp_dp.c
+++ b/drivers/gpu/drm/xlnx/zynqmp_dp.c
@@ -1624,6 +1624,8 @@ static irqreturn_t zynqmp_dp_irq_handler(int irq, void *data)
        u32 status, mask;
 
        status = zynqmp_dp_read(dp, ZYNQMP_DP_INT_STATUS);
+       /* clear status register as soon as we read it */
+       zynqmp_dp_write(dp, ZYNQMP_DP_INT_STATUS, status);
        mask = zynqmp_dp_read(dp, ZYNQMP_DP_INT_MASK);
        if (!(status & ~mask))
                return IRQ_NONE;
@@ -1634,8 +1636,6 @@ static irqreturn_t zynqmp_dp_irq_handler(int irq, void *data)
        if (status & ZYNQMP_DP_INT_CHBUF_OVERFLW_MASK)
                dev_dbg_ratelimited(dp->dev, "overflow interrupt\n");
 
-       zynqmp_dp_write(dp, ZYNQMP_DP_INT_STATUS, status);
-
        if (status & ZYNQMP_DP_INT_VBLANK_START)
                zynqmp_dpsub_drm_handle_vblank(dp->dpsub);