Hi Tomi,
Thank you for the patch.
On Mon, Dec 18, 2023 at 09:54:01AM +0200, Tomi Valkeinen wrote:
> 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.
>
> Signed-off-by: Tomi Valkeinen <tomi.valkeinen@xxxxxxxxxxxxxxxx>
> ---
> .../platform/rockchip/rkisp1/rkisp1-capture.c | 3 +++
> .../media/platform/rockchip/rkisp1/rkisp1-common.h | 2 ++
> .../media/platform/rockchip/rkisp1/rkisp1-csi.c | 3 +++
> .../media/platform/rockchip/rkisp1/rkisp1-dev.c | 22 ++++++++++++++++++++++
> .../media/platform/rockchip/rkisp1/rkisp1-isp.c | 3 +++
> 5 files changed, 33 insertions(+)
>
> diff --git a/drivers/media/platform/rockchip/rkisp1/rkisp1-capture.c b/drivers/media/platform/rockchip/rkisp1/rkisp1-capture.c
> index aebd3c12020b..c381c22135a2 100644
> --- 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;
Given that this is something all drivers that use shared IRQs have to
do, would it make sense to use a standard helper here, such as
pm_runtime_suspended() for instance ? I haven't looked at which one
would be the most appropriate (if any), there's also
pm_runtime_active() and pm_runtime_status_suspended(). That would
simplify this patch.
> +
> 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 4b6b28c05b89..b757f75edecf 100644
> --- 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 b6e47e2f1b94..4202642e0523 100644
> --- 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 acc559652d6e..73cf08a74011 100644
> --- 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 f00873d31c42..78a1f7a1499b 100644
> --- 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;
--
Regards,
Laurent Pinchart
