On Wed, Dec 10, 2025 at 6:24 PM Nirujogi, Pratap <[email protected]> wrote:
>
> Hi Mario,
>
> On 12/9/2025 10:28 PM, Mario Limonciello wrote:
> >
> >
> > On 12/9/2025 7:50 PM, Pratap Nirujogi wrote:
> >> ISP mfd child devices are using genpd and the system suspend-resume
> >> operations between genpd and amdgpu parent device which uses only
> >> runtime suspend-resume are not in sync.
> >>
> >> Linux power manager during suspend-resume resuming the genpd devices
> >> earlier than the amdgpu parent device. This is resulting in the below
> >> warning as SMU is in suspended state when genpd attempts to resume ISP.
> >>
> >> WARNING: CPU: 13 PID: 5435 at
> >> drivers/gpu/drm/amd/amdgpu/../pm/swsmu/amdgpu_smu.c:398
> >> smu_dpm_set_power_gate+0x36f/0x380 [amdgpu]
> >>
> >> To fix this warning isp suspend-resume is handled as part of amdgpu
> >> parent device suspend-resume instead of genpd sequence. Each ISP MFD
> >> child device is marked as dev_pm_syscore_device to skip genpd
> >> suspend-resume and use pm_runtime_force api's to suspend-resume
> >> the devices when callbacks from amdgpu are received.
> >>
> >> Signed-off-by: Gjorgji Rosikopulos <[email protected]>
> >> Signed-off-by: Bin Du <[email protected]>
> >> Signed-off-by: Pratap Nirujogi <[email protected]>
> >
> > Who is the patch author?  If you guys worked together, there should be
> > Co-developed-by tags to represent it.
> >
> >> ---
> >>   drivers/gpu/drm/amd/amdgpu/amdgpu_isp.c | 24 ++++++++++
> >>   drivers/gpu/drm/amd/amdgpu/amdgpu_isp.h |  2 +
> >>   drivers/gpu/drm/amd/amdgpu/isp_v4_1_1.c | 59 +++++++++++++++++++++++++
> >>   3 files changed, 85 insertions(+)
> >>
> >> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_isp.c
> >> b/drivers/gpu/drm/amd/amdgpu/amdgpu_isp.c
> >> index 37270c4dab8d..532f83d783d1 100644
> >> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_isp.c
> >> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_isp.c
> >> @@ -318,12 +318,36 @@ void isp_kernel_buffer_free(void **buf_obj, u64
> >> *gpu_addr, void **cpu_addr)
> >>   }
> >>   EXPORT_SYMBOL(isp_kernel_buffer_free);
> >>   +static int isp_resume(struct amdgpu_ip_block *ip_block)
> >> +{
> >> +    struct amdgpu_device *adev = ip_block->adev;
> >> +    struct amdgpu_isp *isp = &adev->isp;
> >> +
> >> +    if (isp->funcs->hw_resume)
> >> +        return isp->funcs->hw_resume(isp);
> >> +
> >> +    return -ENODEV;
> >> +}
> >> +
> >> +static int isp_suspend(struct amdgpu_ip_block *ip_block)
> >> +{
> >> +    struct amdgpu_device *adev = ip_block->adev;
> >> +    struct amdgpu_isp *isp = &adev->isp;
> >> +
> >> +    if (isp->funcs->hw_suspend)
> >> +        return isp->funcs->hw_suspend(isp);
> >> +
> >> +    return -ENODEV;
> >> +}
> >> +
> >>   static const struct amd_ip_funcs isp_ip_funcs = {
> >>       .name = "isp_ip",
> >>       .early_init = isp_early_init,
> >>       .hw_init = isp_hw_init,
> >>       .hw_fini = isp_hw_fini,
> >>       .is_idle = isp_is_idle,
> >> +    .suspend = isp_suspend,
> >> +    .resume = isp_resume,
> >>       .set_clockgating_state = isp_set_clockgating_state,
> >>       .set_powergating_state = isp_set_powergating_state,
> >>   };
> >> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_isp.h
> >> b/drivers/gpu/drm/amd/amdgpu/amdgpu_isp.h
> >> index d6f4ffa4c97c..9a5d2b1dff9e 100644
> >> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_isp.h
> >> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_isp.h
> >> @@ -38,6 +38,8 @@ struct amdgpu_isp;
> >>   struct isp_funcs {
> >>       int (*hw_init)(struct amdgpu_isp *isp);
> >>       int (*hw_fini)(struct amdgpu_isp *isp);
> >> +    int (*hw_suspend)(struct amdgpu_isp *isp);
> >> +    int (*hw_resume)(struct amdgpu_isp *isp);
> >>   };
> >>     struct amdgpu_isp {
> >> diff --git a/drivers/gpu/drm/amd/amdgpu/isp_v4_1_1.c
> >> b/drivers/gpu/drm/amd/amdgpu/isp_v4_1_1.c
> >> index 4258d3e0b706..560c398e14fc 100644
> >> --- a/drivers/gpu/drm/amd/amdgpu/isp_v4_1_1.c
> >> +++ b/drivers/gpu/drm/amd/amdgpu/isp_v4_1_1.c
> >> @@ -26,6 +26,7 @@
> >>    */
> >>     #include <linux/gpio/machine.h>
> >> +#include <linux/pm_runtime.h>
> >>   #include "amdgpu.h"
> >>   #include "isp_v4_1_1.h"
> >>   @@ -145,6 +146,9 @@ static int isp_genpd_add_device(struct device
> >> *dev, void *data)
> >>           return -ENODEV;
> >>       }
> >>   +    /* The devcies will be managed by the pm ops from the parent */
> >
> > devices
> >
> >> +    dev_pm_syscore_device(dev, true);
> >> +
> >>   exit:
> >>       /* Continue to add */
> >>       return 0;
> >> @@ -177,12 +181,65 @@ static int isp_genpd_remove_device(struct
> >> device *dev, void *data)
> >>           drm_err(&adev->ddev, "Failed to remove dev from genpd
> >> %d\n", ret);
> >>           return -ENODEV;
> >>       }
> >> +    dev_pm_syscore_device(dev, false);
> >>     exit:
> >>       /* Continue to remove */
> >>       return 0;
> >>   }
> >>   +static int isp_suspend_device(struct device *dev, void *data)
> >> +{
> >> +    struct platform_device *pdev = container_of(dev, struct
> >> platform_device, dev);
> >> +
> >> +    if (!dev->type || !dev->type->name)
> >> +        return 0;
> >> +    if (strncmp(dev->type->name, "mfd_device", 10))
> >> +        return 0;
> >> +    if (!strncmp(pdev->mfd_cell->name, "amdisp-pinctrl", 14))
> >> +        return 0;
> >
> > Could we store the mfd_cell pointer instead and just compare the
> > pointers?
>
> I don't think I can do a pointer comparision to identify the correct
> mfd_cell, string comparision seems like required in this case.
>
> Its because when isp mfd child devices are created using
> mfd_add_hotplug_devices(), it is not returning the pdev or mfd_cell handles
> to store in the amdgpu_isp and later use in suspend/resume to compare
> with incoming pdev->mfd_cell to detect the correct the device.
>
> The mfd-core is doing a kmemdup of mfd_cells data passed to
> mfd_add_hotplug_devices() to create the platform device.
>
> https://github.com/torvalds/linux/blob/master/drivers/mfd/mfd-core.c#L163
>
> I'm considering to add this function to check for valid isp mfd child
> devices that are allowed to do suspend-resume, this can minimize the
> checks, but still cannot eliminate the string comparsion, please let us
> know your thoughts.

Can you do something like what was done in the acp code?  See:

commit 4fce6b64ec8bcd0694f221906952d2880ed8ae31
Author: Brady Norander <[email protected]>
Date:   Tue Mar 25 17:05:17 2025 -0400

    drm/amdgpu: use static ids for ACP platform devs

    mfd_add_hotplug_devices() assigns child platform devices with
    PLATFORM_DEVID_AUTO, but the ACP machine drivers expect the platform
    device names to never change. Use mfd_add_devices() instead and give
    each cell a unique id.

    Signed-off-by: Brady Norander <[email protected]>
    Signed-off-by: Alex Deucher <[email protected]>

Alex

>
> static bool is_valid_mfd_device(struct platform_device *pdev)
> {
>      const struct mfd_cell *mc = mfd_get_cell(pdev);
>      if (!mc)
>          return false;
>      if (!strncmp(mc->name, "amdisp-pinctrl", 14))
>          return false;
>      return true;
> }
>
> Thanks,
>
> Pratap
>
> >
> >> +
> >> +    return pm_runtime_force_suspend(dev);
> >> +}
> >> +
> >> +static int isp_resume_device(struct device *dev, void *data)
> >> +{
> >> +    struct platform_device *pdev = container_of(dev, struct
> >> platform_device, dev);
> >> +
> >> +    if (!dev->type || !dev->type->name)
> >> +        return 0;
> >> +    if (strncmp(dev->type->name, "mfd_device", 10))
> >> +        return 0;
> >> +    if (!strncmp(pdev->mfd_cell->name, "amdisp-pinctrl", 14))
> >> +        return 0;
> >
> > same comment as above
> >
> >> +
> >> +    return pm_runtime_force_resume(dev);
> >> +}
> >> +
> >> +static int isp_v4_1_1_hw_suspend(struct amdgpu_isp *isp)
> >> +{
> >> +    int r;
> >> +
> >> +    r = device_for_each_child(isp->parent, NULL,
> >> +                  isp_suspend_device);
> >> +    if (r)
> >> +        dev_err(isp->parent, "failed to suspend hw devices (%d)\n", r);
> >> +
> >> +    return 0;
> >
> > Shouldn't you return r?
> >
> >> +}
> >> +
> >> +static int isp_v4_1_1_hw_resume(struct amdgpu_isp *isp)
> >> +{
> >> +    int r;
> >> +
> >> +    r = device_for_each_child(isp->parent, NULL,
> >> +                  isp_resume_device);
> >> +    if (r)
> >> +        dev_err(isp->parent, "failed to resume hw device (%d)\n", r);
> >> +
> >> +    return 0;
> >
> > Shouldn't you return r?
> >
> >> +}
> >> +
> >>   static int isp_v4_1_1_hw_init(struct amdgpu_isp *isp)
> >>   {
> >>       const struct software_node *amd_camera_node, *isp4_node;
> >> @@ -369,6 +426,8 @@ static int isp_v4_1_1_hw_fini(struct amdgpu_isp
> >> *isp)
> >>   static const struct isp_funcs isp_v4_1_1_funcs = {
> >>       .hw_init = isp_v4_1_1_hw_init,
> >>       .hw_fini = isp_v4_1_1_hw_fini,
> >> +    .hw_suspend = isp_v4_1_1_hw_suspend,
> >> +    .hw_resume = isp_v4_1_1_hw_resume,
> >>   };
> >>     void isp_v4_1_1_set_isp_funcs(struct amdgpu_isp *isp)
> >

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