Re: [PATCH v2] HID: amd_sfh: Use shared interrupts

[Basavaraj Natikar <bnatikar@amd.com>]

On 10/23/2026 1:48 PM, Ho Jie Feng wrote:
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>
> The AMD SFH driver requests interrupts without IRQF_SHARED.
> This can cause VFIO PCI passthrough initialization to fail
> when a passed-through device shares the interrupt with AMD MP2.
>
> Request the interrupt with IRQF_SHARED. Check for a pending MP2
> interrupt before clearing and acknowledging it, and return IRQ_NONE
> when no MP2 interrupt is pending so the interrupt can be shared with
> other devices.
>
> On an AMD Ryzen 7 7735HS host running 7.0.0-38-generic kernel
> from Ubuntu, trying to pass through an xHCI controller
> (1022:161d, 0000:e6:00.3) fails with this message:
>
>    genirq: Flags mismatch irq 45.
>    00200080 (vfio-intx(0000:e6:00.3)) vs. 00200000 (pcie_mp2_amd)
>
> QEMU reports:
>
>    vfio 0000:e6:00.3: Failed to set up TRIGGER eventfd signaling for
>    interrupt INTX-0: VFIO_DEVICE_SET_IRQS failure: Device or resource busy
>
> With this change, the passthrough is successful through VFIO
> on the same host.
>
> Fixes: 7f016b35ca76 ("HID: amd_sfh: Add interrupt handler to process interrupts")
> Cc: stable@vger.kernel.org
> Signed-off-by: Ho Jie Feng <hjf3108@gmail.com>
> ---
>   drivers/hid/amd-sfh-hid/amd_sfh_common.h |  6 +++---
>   drivers/hid/amd-sfh-hid/amd_sfh_pcie.c   | 18 ++++++++++++------
>   2 files changed, 15 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/hid/amd-sfh-hid/amd_sfh_common.h b/drivers/hid/amd-sfh-hid/amd_sfh_common.h
> index e8cc7f1d289cc..4481a50359de6 100644
> --- a/drivers/hid/amd-sfh-hid/amd_sfh_common.h
> +++ b/drivers/hid/amd-sfh-hid/amd_sfh_common.h
> @@ -85,7 +85,7 @@ struct amd_mp2_ops {
>          void (*stop)(struct amd_mp2_dev *privdata, u16 sensor_idx);
>          void (*stop_all)(struct amd_mp2_dev *privdata);
>          int (*response)(struct amd_mp2_dev *mp2, u8 sid, u32 sensor_sts);
> -       void (*clear_intr)(struct amd_mp2_dev *privdata);
> +       bool (*clear_intr)(struct amd_mp2_dev *privdata);
>          int (*init_intr)(struct amd_mp2_dev *privdata);
>          int (*discovery_status)(struct amd_mp2_dev *privdata);
>          void (*suspend)(struct amd_mp2_dev *mp2);
> @@ -100,9 +100,9 @@ struct amd_mp2_ops {
>
>   void amd_sfh_work(struct work_struct *work);
>   void amd_sfh_work_buffer(struct work_struct *work);
> -void amd_sfh_clear_intr_v2(struct amd_mp2_dev *privdata);
> +bool amd_sfh_clear_intr_v2(struct amd_mp2_dev *privdata);
>   int amd_sfh_irq_init_v2(struct amd_mp2_dev *privdata);
> -void amd_sfh_clear_intr(struct amd_mp2_dev *privdata);
> +bool amd_sfh_clear_intr(struct amd_mp2_dev *privdata);
>   int amd_sfh_irq_init(struct amd_mp2_dev *privdata);
>
>   static inline u64 amd_get_c2p_val(struct amd_mp2_dev *mp2, u32 idx)
> diff --git a/drivers/hid/amd-sfh-hid/amd_sfh_pcie.c b/drivers/hid/amd-sfh-hid/amd_sfh_pcie.c
> index b3cb13b8c5e87..f48a096a6d2bc 100644
> --- a/drivers/hid/amd-sfh-hid/amd_sfh_pcie.c
> +++ b/drivers/hid/amd-sfh-hid/amd_sfh_pcie.c
> @@ -103,25 +103,31 @@ static void amd_stop_all_sensor_v2(struct amd_mp2_dev *privdata)
>          writel(cmd_base.ul, privdata->mmio + AMD_C2P_MSG0);
>   }
>
> -void amd_sfh_clear_intr_v2(struct amd_mp2_dev *privdata)
> +bool amd_sfh_clear_intr_v2(struct amd_mp2_dev *privdata)
>   {
>          if (readl(privdata->mmio + amd_get_p2c_val(privdata, 4))) {
>                  writel(0, privdata->mmio + amd_get_p2c_val(privdata, 4));
>                  writel(0xf, privdata->mmio + amd_get_p2c_val(privdata, 5));
> +               return true;
>          }
> +
> +       return false;
>   }
>
> -void amd_sfh_clear_intr(struct amd_mp2_dev *privdata)
> +bool amd_sfh_clear_intr(struct amd_mp2_dev *privdata)
>   {
>          if (privdata->mp2_ops->clear_intr)
> -               privdata->mp2_ops->clear_intr(privdata);
> +               return privdata->mp2_ops->clear_intr(privdata);
> +
> +       return false;
>   }
>
>   static irqreturn_t amd_sfh_irq_handler(int irq, void *data)
>   {
> -       amd_sfh_clear_intr(data);
> +       if (amd_sfh_clear_intr(data))
> +               return IRQ_HANDLED;
>
> -       return IRQ_HANDLED;
> +       return IRQ_NONE;
>   }
>
>   int amd_sfh_irq_init_v2(struct amd_mp2_dev *privdata)
> @@ -129,7 +135,7 @@ int amd_sfh_irq_init_v2(struct amd_mp2_dev *privdata)
>          pcim_intx(privdata->pdev, true);
>
>          return devm_request_irq(&privdata->pdev->dev, privdata->pdev->irq,
> -                               amd_sfh_irq_handler, 0, DRIVER_NAME, privdata);
> +                               amd_sfh_irq_handler, IRQF_SHARED, DRIVER_NAME, privdata);
>   }
>
>   static int amd_sfh_dis_sts_v2(struct amd_mp2_dev *privdata)

Acked-by: Basavaraj Natikar <Basavaraj.Natikar@amd.com>


Thanks,
--
Basavaraj

>
> base-commit: 2c2fe95ab19b09bef7391e3e5cdf8146d09792b6
> --
> 2.55.0
>