[PATCH 3/4] media: rkisp1: Fix IRQ handling due to shared interrupts

Tomi Valkeinen
2023-12-05T08:10:31Z

The driver requests the interrupts as IRQF_SHARED, so the interrupt
handlers can be called at any time. If such a call happens while the ISP
is powered down, the SoC will hang as the driver tries to access the
ISP registers.

Fix this by adding a new field, 'irqs_enabled', which is used to bail
out from the interrupt handler when the ISP is not operational.

Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
---
.../media/platform/rockchip/rkisp1/rkisp1-capture.c | 3 +++
.../media/platform/rockchip/rkisp1/rkisp1-common.h | 2 ++
drivers/media/platform/rockchip/rkisp1/rkisp1-csi.c | 3 +++
drivers/media/platform/rockchip/rkisp1/rkisp1-dev.c | 21 +++++++++++++++++++++
drivers/media/platform/rockchip/rkisp1/rkisp1-isp.c | 3 +++
5 files changed, 32 insertions(+)

diff --git a/drivers/media/platform/rockchip/rkisp1/rkisp1-capture.c b/drivers/media/platform/rockchip/rkisp1/rkisp1-capture.c
index b50b044d22af..e92067897f28 100644
--- a/drivers/media/platform/rockchip/rkisp1/rkisp1-capture.c
+++ b/drivers/media/platform/rockchip/rkisp1/rkisp1-capture.c
@@ -779,6 +779,9 @@ irqreturn_t rkisp1_capture_isr(int irq, void *ctx)
unsigned int i;
u32 status;

+ if (!rkisp1->irqs_enabled)
+ return IRQ_NONE;
+
status = rkisp1_read(rkisp1, RKISP1_CIF_MI_MIS);
if (!status)
return IRQ_NONE;
diff --git a/drivers/media/platform/rockchip/rkisp1/rkisp1-common.h b/drivers/media/platform/rockchip/rkisp1/rkisp1-common.h
index ec28907d978e..7f97fdf6e24c 100644
--- a/drivers/media/platform/rockchip/rkisp1/rkisp1-common.h
+++ b/drivers/media/platform/rockchip/rkisp1/rkisp1-common.h
@@ -465,6 +465,7 @@ struct rkisp1_debug {
* @debug: debug params to be exposed on debugfs
* @info: version-specific ISP information
* @irqs: IRQ line numbers
+ * @irqs_enabled: the hardware is enabled and can cause interrupts
*/
struct rkisp1_device {
void __iomem *base_addr;
@@ -488,6 +489,7 @@ struct rkisp1_device {
struct rkisp1_debug debug;
const struct rkisp1_info *info;
int irqs[RKISP1_NUM_IRQS];
+ bool irqs_enabled;
};

/*
diff --git a/drivers/media/platform/rockchip/rkisp1/rkisp1-csi.c b/drivers/media/platform/rockchip/rkisp1/rkisp1-csi.c
index 47f4353a1784..f6b54654b435 100644
--- a/drivers/media/platform/rockchip/rkisp1/rkisp1-csi.c
+++ b/drivers/media/platform/rockchip/rkisp1/rkisp1-csi.c
@@ -184,6 +184,9 @@ irqreturn_t rkisp1_csi_isr(int irq, void *ctx)
struct rkisp1_device *rkisp1 = dev_get_drvdata(dev);
u32 val, status;

+ if (!rkisp1->irqs_enabled)
+ return IRQ_NONE;
+
status = rkisp1_read(rkisp1, RKISP1_CIF_MIPI_MIS);
if (!status)
return IRQ_NONE;
diff --git a/drivers/media/platform/rockchip/rkisp1/rkisp1-dev.c b/drivers/media/platform/rockchip/rkisp1/rkisp1-dev.c
index 1d60f4b8bd09..fbe03f7864e3 100644
--- a/drivers/media/platform/rockchip/rkisp1/rkisp1-dev.c
+++ b/drivers/media/platform/rockchip/rkisp1/rkisp1-dev.c
@@ -306,6 +306,23 @@ static int __maybe_unused rkisp1_runtime_suspend(struct device *dev)
{
struct rkisp1_device *rkisp1 = dev_get_drvdata(dev);

+ rkisp1->irqs_enabled = false;
+ /* Make sure the IRQ handler will see the above */
+ mb();
+
+ /*
+ * Wait until any running IRQ handler has returned. The IRQ handler
+ * may get called even after this (as it's a shared interrupt line)
+ * but the 'irqs_enabled' flag will make the handler return immediately.
+ */
+ for (unsigned int i = 0; i < RKISP1_NUM_IRQS; ++i) {
+ if (rkisp1->irqs[i] == -1)
+ continue;
+
+ if (i == 0 || rkisp1->irqs[i - 1] != rkisp1->irqs[i])
+ synchronize_irq(rkisp1->irqs[i]);
+ }
+
clk_bulk_disable_unprepare(rkisp1->clk_size, rkisp1->clks);
return pinctrl_pm_select_sleep_state(dev);
}
@@ -322,6 +339,10 @@ static int __maybe_unused rkisp1_runtime_resume(struct device *dev)
if (ret)
return ret;

+ rkisp1->irqs_enabled = true;
+ /* Make sure the IRQ handler will see the above */
+ mb();
+
return 0;
}

diff --git a/drivers/media/platform/rockchip/rkisp1/rkisp1-isp.c b/drivers/media/platform/rockchip/rkisp1/rkisp1-isp.c
index dafbfd230542..d6b8786661ad 100644
--- a/drivers/media/platform/rockchip/rkisp1/rkisp1-isp.c
+++ b/drivers/media/platform/rockchip/rkisp1/rkisp1-isp.c
@@ -1082,6 +1082,9 @@ irqreturn_t rkisp1_isp_isr(int irq, void *ctx)
struct rkisp1_device *rkisp1 = dev_get_drvdata(dev);
u32 status, isp_err;

+ if (!rkisp1->irqs_enabled)
+ return IRQ_NONE;
+
status = rkisp1_read(rkisp1, RKISP1_CIF_ISP_MIS);
if (!status)
return IRQ_NONE;

--
2.34.1