[PATCH v10 33/69] drm/rockchip: dw_hdmi_qp: Avoid spurious HPD IRQ thread wakeups

The RK3576 and RK3588 HPD hardirq handlers read shared status registers
and currently wake the threaded handler whenever any bit in those
registers is set.  This can wake the HDMI IRQ thread for unrelated
status bits, and on RK3588 can also wake the thread for the other HDMI
port.

Mask the status value with the SoC-specific HPD interrupt bit before
deciding whether to wake the threaded handler.  On RK3588, select the
HDMI0 or HDMI1 HPD bit according to the instance port id.

No stable backport is needed.  The issue may only cause spurious IRQ
thread wakeups and does not cause functional breakage.

Reported-by: Sashiko <[email protected]>
Closes: https://lore.kernel.org/all/[email protected]/
Tested-by: Diederik de Haas <[email protected]>  # NanoPC-T6 LTS, Rock 5B
Signed-off-by: Cristian Ciocaltea <[email protected]>
---
 drivers/gpu/drm/rockchip/dw_hdmi_qp-rockchip.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/rockchip/dw_hdmi_qp-rockchip.c b/drivers/gpu/drm/rockchip/dw_hdmi_qp-rockchip.c
index 36043bf82273..f5342c5f457b 100644
--- a/drivers/gpu/drm/rockchip/dw_hdmi_qp-rockchip.c
+++ b/drivers/gpu/drm/rockchip/dw_hdmi_qp-rockchip.c
@@ -34,6 +34,7 @@
 
 #define RK3576_IOC_HDMI_HPD_STATUS	0xa440
 #define RK3576_HDMI_LEVEL_INT		BIT(3)
+#define RK3576_HDMI_OHPD_INT		BIT(4)
 
 #define RK3576_VO0_GRF_SOC_CON1		0x0004
 #define RK3576_HDMI_FRL_MOD		BIT(0)
@@ -64,7 +65,9 @@
 #define RK3588_HPD_HDMI1_IO_EN_MASK	BIT(13)
 #define RK3588_GRF_SOC_STATUS1		0x0384
 #define RK3588_HDMI0_LEVEL_INT		BIT(16)
+#define RK3588_HDMI0_OHPD_INT		BIT(17)
 #define RK3588_HDMI1_LEVEL_INT		BIT(24)
+#define RK3588_HDMI1_OHPD_INT		BIT(25)
 #define RK3588_GRF_VO1_CON3		0x000c
 #define RK3588_GRF_VO1_CON6		0x0018
 #define RK3588_COLOR_DEPTH_MASK		GENMASK(7, 4)
@@ -348,7 +351,7 @@ static irqreturn_t dw_hdmi_qp_rk3576_hardirq(int irq, void *dev_id)
 	u32 intr_stat, val;
 
 	regmap_read(hdmi->regmap, RK3576_IOC_HDMI_HPD_STATUS, &intr_stat);
-	if (intr_stat) {
+	if (intr_stat & RK3576_HDMI_OHPD_INT) {
 		val = FIELD_PREP_WM16(RK3576_HDMI_HPD_INT_MSK, 1);
 
 		regmap_write(hdmi->regmap, RK3576_IOC_MISC_CON0, val);
@@ -381,6 +384,8 @@ static irqreturn_t dw_hdmi_qp_rk3588_hardirq(int irq, void *dev_id)
 
 	regmap_read(hdmi->regmap, RK3588_GRF_SOC_STATUS1, &intr_stat);
 
+	intr_stat &= hdmi->port_id ? RK3588_HDMI1_OHPD_INT : RK3588_HDMI0_OHPD_INT;
+
 	if (intr_stat) {
 		if (hdmi->port_id)
 			val = FIELD_PREP_WM16(RK3588_HDMI1_HPD_INT_MSK, 1);

-- 
2.55.0