media: rkisp1: Fix IRQ handling due to shared interrupts

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.

This can be reproduced even without the platform sharing the IRQ line:
Enable CONFIG_DEBUG_SHIRQ and unload the driver, and the board will
hang.

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.

Link: https://lore.kernel.org/r/20231218-rkisp-shirq-fix-v1-2-173007628248@ideasonboard.com
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>

diff --git a/drivers/media/platform/rockchip/rkisp1/rkisp1-capture.c b/drivers/media/platform/rockchip/rkisp1/rkisp1-capture.c
index aebd3c12020bfd5d104c089354da0557de93547d..c381c22135a217b71e82f8282699cfbe14749ded 100644 (file)
--- a/drivers/media/platform/rockchip/rkisp1/rkisp1-capture.c
+++ b/drivers/media/platform/rockchip/rkisp1/rkisp1-capture.c
@@ -725,6 +725,9 @@ 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 4b6b28c05b8916b7e5e079b6d2791009907c22db..b757f75edecf75256525e378151fe217c88ef2c4 100644 (file)
--- a/drivers/media/platform/rockchip/rkisp1/rkisp1-common.h
+++ b/drivers/media/platform/rockchip/rkisp1/rkisp1-common.h
@@ -450,6 +450,7 @@ 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;
@@ -471,6 +472,7 @@ 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 b6e47e2f1b94916e51ec86b38d12b37ae186609d..4202642e052392a946761ecb76d3cfa771956e07 100644 (file)
--- a/drivers/media/platform/rockchip/rkisp1/rkisp1-csi.c
+++ b/drivers/media/platform/rockchip/rkisp1/rkisp1-csi.c
@@ -196,6 +196,9 @@ 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 acc559652d6ebae663993105af65e46c9ce5e321..73cf08a740118c05328fdd3f1a9d52a6e935c4e0 100644 (file)
--- a/drivers/media/platform/rockchip/rkisp1/rkisp1-dev.c
+++ b/drivers/media/platform/rockchip/rkisp1/rkisp1-dev.c
@@ -305,6 +305,24 @@ 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 il = 0; il < ARRAY_SIZE(rkisp1->irqs); ++il) {
+               if (rkisp1->irqs[il] == -1)
+                       continue;
+
+               /* Skip if the irq line is the same as previous */
+               if (il == 0 || rkisp1->irqs[il - 1] != rkisp1->irqs[il])
+                       synchronize_irq(rkisp1->irqs[il]);
+       }
+
        clk_bulk_disable_unprepare(rkisp1->clk_size, rkisp1->clks);
        return pinctrl_pm_select_sleep_state(dev);
 }
@@ -321,6 +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 f00873d31c42b702d239e9e9fefcb8eddb599275..78a1f7a1499be84f15b94d75b30266dfb8c720ce 100644 (file)
--- a/drivers/media/platform/rockchip/rkisp1/rkisp1-isp.c
+++ b/drivers/media/platform/rockchip/rkisp1/rkisp1-isp.c
@@ -976,6 +976,9 @@ 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;