[DPU PATCH v3] drm/msm: Use atomic private_obj instead of subclassing
Jeykumar Sankaran
jsanka at codeaurora.org
Fri May 25 01:16:41 UTC 2018
On 2018-03-20 04:01, Archit Taneja wrote:
> Hi,
>
> On Tuesday 20 March 2018 01:28 AM, Sean Paul wrote:
>> Instead of subclassing atomic state, store driver private data in
>> private_obj/state. This allows us to remove the swap_state driver hook
>> for mdp5 and get closer to using the atomic helpers entirely.
>>
>> Changes in v2:
>> - Use state->state in disp duplicate_state callback (Jeykumar)
>> Changes in v3:
>> - Update comment describing msm_kms_state (Jeykumar)
>>
>
> One difference w.r.t the patchset
> "drm/msm/mdp5: Use the new private_obj state" is that this
> adds the atomic private_obj for all kms backends, whereas the one
> I'd done originally just added it for mdp5, so this patch set
> is better in that respect.
>
> The other difference is how we 'get' the private state. In this patch,
> the helper drm_atomic_get_private_obj_state() is used every time to
> get the private object state.
>
> I'd tried to do the same initially, but I noticed that
> drm_atomic_get_private_obj_state() doesn't return the correct
> state post swapping of states. So, instead of relying on the helper,
> I created a helper called mdp5_get_existing_global_state() that
> returns the desired state(the state pointer in
> msm_kms>state->base.state
> in this patch) in all funcs that are called post-swap.
>
>
> You could read about the issue on the the thread: "[RFC 1/3]
> drm/msm/mdp5: Add global state as a private atomic object"
>
> The problem was quite apparent with db410c, where SMP blocks are
> assigned to planes. If the latest SMP state isn't referred when
> configuring SMP registers, we see underruns immediately.
>
> An easy way to reproduce this is to use modset on db410c. I think
> it might occur with this patch too. It might be worth trying it
> out.
>
> Thanks,
> Archit
>
Hello Archit, Now that I am trying to use the private obj to maintain
resource pool in DPU, I realize the need for retrieving existing / new
state API's. Don't you think this support is missing in the DRM core
fwk, considering how drm_atomic_get_existing_XXXX_state,
drm_atomic_get_old_XXXX_state, drm_atomic_get_new_XXXX_state API's are
available for CRTC/PLANE and CONNECTORS but not for private_obj's?
Thanks,
Jeykumar S.
>> Cc: Jeykumar Sankaran <jsanka at codeaurora.org>
>> Reviewed-by: Jeykumar Sankaran <jsanka at codeaurora.org>
>> Signed-off-by: Sean Paul <seanpaul at chromium.org>
>> ---
>> drivers/gpu/drm/msm/disp/mdp5/mdp5_kms.c | 37 ++++++--------
>> drivers/gpu/drm/msm/msm_atomic.c | 30 -----------
>> drivers/gpu/drm/msm/msm_drv.c | 65
>> ++++++++++++++++++++++--
>> drivers/gpu/drm/msm/msm_drv.h | 4 +-
>> drivers/gpu/drm/msm/msm_kms.h | 27 +++++-----
>> 5 files changed, 94 insertions(+), 69 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/msm/disp/mdp5/mdp5_kms.c
>> b/drivers/gpu/drm/msm/disp/mdp5/mdp5_kms.c
>> index 6d8e3a9a6fc0..f1a248419655 100644
>> --- a/drivers/gpu/drm/msm/disp/mdp5/mdp5_kms.c
>> +++ b/drivers/gpu/drm/msm/disp/mdp5/mdp5_kms.c
>> @@ -74,36 +74,32 @@ struct mdp5_state *mdp5_get_state(struct
>> drm_atomic_state *s)
>> {
>> struct msm_drm_private *priv = s->dev->dev_private;
>> struct mdp5_kms *mdp5_kms = to_mdp5_kms(to_mdp_kms(priv->kms));
>> - struct msm_kms_state *state = to_kms_state(s);
>> - struct mdp5_state *new_state;
>> + struct msm_kms_state *kms_state;
>> int ret;
>>
>> - if (state->state)
>> - return state->state;
>> -
>> ret = drm_modeset_lock(&mdp5_kms->state_lock, s->acquire_ctx);
>> if (ret)
>> return ERR_PTR(ret);
>>
>> - new_state = kmalloc(sizeof(*mdp5_kms->state), GFP_KERNEL);
>> - if (!new_state)
>> - return ERR_PTR(-ENOMEM);
>> + kms_state = msm_kms_get_state(s);
>> + if (IS_ERR_OR_NULL(kms_state))
>> + return (struct mdp5_state *)kms_state; /* casting ERR_PTR */
>>
>> - /* Copy state: */
>> - new_state->hwpipe = mdp5_kms->state->hwpipe;
>> - new_state->hwmixer = mdp5_kms->state->hwmixer;
>> - if (mdp5_kms->smp)
>> - new_state->smp = mdp5_kms->state->smp;
>> + return kms_state->state;
>> +}
>>
>> - state->state = new_state;
>> +static void *mdp5_duplicate_state(void *state)
>> +{
>> + if (!state)
>> + return kzalloc(sizeof(struct mdp5_state), GFP_KERNEL);
>>
>> - return new_state;
>> + return kmemdup(state, sizeof(struct mdp5_state), GFP_KERNEL);
>> }
>>
>> -static void mdp5_swap_state(struct msm_kms *kms, struct
>> drm_atomic_state *state)
>> +static void mdp5_destroy_state(void *state)
>> {
>> - struct mdp5_kms *mdp5_kms = to_mdp5_kms(to_mdp_kms(kms));
>> - swap(to_kms_state(state)->state, mdp5_kms->state);
>> + struct mdp5_state *mdp_state = state;
>> + kfree(mdp_state);
>> }
>>
>> static void mdp5_prepare_commit(struct msm_kms *kms, struct
>> drm_atomic_state *state)
>> @@ -229,7 +225,8 @@ static const struct mdp_kms_funcs kms_funcs = {
>> .irq = mdp5_irq,
>> .enable_vblank = mdp5_enable_vblank,
>> .disable_vblank = mdp5_disable_vblank,
>> - .swap_state = mdp5_swap_state,
>> + .duplicate_state = mdp5_duplicate_state,
>> + .destroy_state = mdp5_destroy_state,
>> .prepare_commit = mdp5_prepare_commit,
>> .complete_commit = mdp5_complete_commit,
>> .wait_for_crtc_commit_done = mdp5_wait_for_crtc_commit_done,
>> @@ -726,8 +723,6 @@ static void mdp5_destroy(struct platform_device
>> *pdev)
>>
>> if (mdp5_kms->rpm_enabled)
>> pm_runtime_disable(&pdev->dev);
>> -
>> - kfree(mdp5_kms->state);
>> }
>>
>> static int construct_pipes(struct mdp5_kms *mdp5_kms, int cnt,
>> diff --git a/drivers/gpu/drm/msm/msm_atomic.c
>> b/drivers/gpu/drm/msm/msm_atomic.c
>> index 7e54eb65d096..1f53262ea46b 100644
>> --- a/drivers/gpu/drm/msm/msm_atomic.c
>> +++ b/drivers/gpu/drm/msm/msm_atomic.c
>> @@ -169,9 +169,6 @@ int msm_atomic_commit(struct drm_device *dev,
>> */
>> BUG_ON(drm_atomic_helper_swap_state(state, false) < 0);
>>
>> - if (to_kms_state(state)->state)
>> - priv->kms->funcs->swap_state(priv->kms, state);
>> -
>> /*
>> * Provide the driver a chance to prepare for output fences. This
>> is
>> * done after the point of no return, but before asynchronous
>> commits
>> @@ -210,30 +207,3 @@ int msm_atomic_commit(struct drm_device *dev,
>> drm_atomic_helper_cleanup_planes(dev, state);
>> return ret;
>> }
>> -
>> -struct drm_atomic_state *msm_atomic_state_alloc(struct drm_device
>> *dev)
>> -{
>> - struct msm_kms_state *state = kzalloc(sizeof(*state), GFP_KERNEL);
>> -
>> - if (!state || drm_atomic_state_init(dev, &state->base) < 0) {
>> - kfree(state);
>> - return NULL;
>> - }
>> -
>> - return &state->base;
>> -}
>> -
>> -void msm_atomic_state_clear(struct drm_atomic_state *s)
>> -{
>> - struct msm_kms_state *state = to_kms_state(s);
>> - drm_atomic_state_default_clear(&state->base);
>> - kfree(state->state);
>> - state->state = NULL;
>> -}
>> -
>> -void msm_atomic_state_free(struct drm_atomic_state *state)
>> -{
>> - kfree(to_kms_state(state)->state);
>> - drm_atomic_state_default_release(state);
>> - kfree(state);
>> -}
>> diff --git a/drivers/gpu/drm/msm/msm_drv.c
>> b/drivers/gpu/drm/msm/msm_drv.c
>> index 5219792e93bc..4c0740dc7854 100644
>> --- a/drivers/gpu/drm/msm/msm_drv.c
>> +++ b/drivers/gpu/drm/msm/msm_drv.c
>> @@ -121,9 +121,62 @@ static const struct drm_mode_config_funcs
>> mode_config_funcs = {
>> .output_poll_changed = msm_fb_output_poll_changed,
>> .atomic_check = drm_atomic_helper_check,
>> .atomic_commit = msm_atomic_commit,
>> - .atomic_state_alloc = msm_atomic_state_alloc,
>> - .atomic_state_clear = msm_atomic_state_clear,
>> - .atomic_state_free = msm_atomic_state_free,
>> +};
>> +
>> +static inline
>> +struct msm_kms *obj_to_kms(struct drm_private_obj *obj)
>> +{
>> + return container_of(obj, struct msm_kms, base);
>> +}
>> +
>> +static inline
>> +struct msm_kms_state *state_to_kms_state(struct drm_private_state
>> *state)
>> +{
>> + return container_of(state, struct msm_kms_state, base);
>> +}
>> +
>> +struct msm_kms_state *msm_kms_get_state(struct drm_atomic_state *s)
>> +{
>> + struct msm_drm_private *priv = s->dev->dev_private;
>> + struct drm_private_obj *obj = &priv->kms->base;
>> + struct drm_private_state *state;
>> +
>> + state = drm_atomic_get_private_obj_state(s, obj);
>> + if (IS_ERR_OR_NULL(state))
>> + return (struct msm_kms_state *)state; /* casting ERR_PTR */
>> +
>> + return state_to_kms_state(state);
>> +}
>> +
>> +static struct drm_private_state *
>> +msm_kms_duplicate_state(struct drm_private_obj *obj)
>> +{
>> + struct msm_kms *kms = obj_to_kms(obj);
>> + struct msm_kms_state *state = state_to_kms_state(obj->state);
>> + struct msm_kms_state *new_state;
>> +
>> + if (kms->funcs->duplicate_state)
>> + new_state = kms->funcs->duplicate_state(state->state);
>> +
>> + __drm_atomic_helper_private_obj_duplicate_state(obj,
>> &new_state->base);
>> +
>> + return &new_state->base;
>> +}
>> +
>> +static void msm_kms_destroy_state(struct drm_private_obj *obj,
>> + struct drm_private_state *state)
>> +{
>> + struct msm_kms *kms = obj_to_kms(obj);
>> + struct msm_kms_state *kms_state = state_to_kms_state(obj->state);
>> +
>> + if (kms->funcs->destroy_state)
>> + kms->funcs->destroy_state(kms_state->state);
>> + kfree(kms_state);
>> +}
>> +
>> +static const struct drm_private_state_funcs kms_state_funcs = {
>> + .atomic_duplicate_state = msm_kms_duplicate_state,
>> + .atomic_destroy_state = msm_kms_destroy_state,
>> };
>>
>> #ifdef CONFIG_DRM_MSM_REGISTER_LOGGING
>> @@ -341,6 +394,8 @@ static int msm_drm_uninit(struct device *dev)
>> }
>> }
>>
>> + drm_atomic_private_obj_fini(&kms->base);
>> +
>> msm_gem_shrinker_cleanup(ddev);
>>
>> drm_kms_helper_poll_fini(ddev);
>> @@ -770,6 +825,10 @@ static int msm_drm_init(struct device *dev,
>> struct drm_driver *drv)
>> }
>> #endif
>>
>> + drm_atomic_private_obj_init(&kms->base,
>> + &kms->state.base,
>> + &kms_state_funcs);
>> +
>> /* perform subdriver post initialization */
>> if (kms && kms->funcs && kms->funcs->postinit) {
>> ret = kms->funcs->postinit(kms);
>> diff --git a/drivers/gpu/drm/msm/msm_drv.h
>> b/drivers/gpu/drm/msm/msm_drv.h
>> index 292496b682e8..8cab333df717 100644
>> --- a/drivers/gpu/drm/msm/msm_drv.h
>> +++ b/drivers/gpu/drm/msm/msm_drv.h
>> @@ -598,9 +598,7 @@ struct msm_format {
>>
>> int msm_atomic_commit(struct drm_device *dev,
>> struct drm_atomic_state *state, bool nonblock);
>> -struct drm_atomic_state *msm_atomic_state_alloc(struct drm_device
>> *dev);
>> -void msm_atomic_state_clear(struct drm_atomic_state *state);
>> -void msm_atomic_state_free(struct drm_atomic_state *state);
>> +struct msm_kms_state *msm_kms_get_state(struct drm_atomic_state
>> *state);
>>
>> void msm_gem_unmap_vma(struct msm_gem_address_space *aspace,
>> struct msm_gem_vma *vma, struct sg_table *sgt);
>> diff --git a/drivers/gpu/drm/msm/msm_kms.h
>> b/drivers/gpu/drm/msm/msm_kms.h
>> index 09ba1e79db50..5c1bcaf65fd9 100644
>> --- a/drivers/gpu/drm/msm/msm_kms.h
>> +++ b/drivers/gpu/drm/msm/msm_kms.h
>> @@ -57,6 +57,8 @@ struct msm_kms_funcs {
>> void (*disable_vblank)(struct msm_kms *kms, struct drm_crtc *crtc);
>> /* swap global atomic state: */
>> void (*swap_state)(struct msm_kms *kms, struct drm_atomic_state
>> *state);
>> + void *(*duplicate_state)(void *state);
>> + void (*destroy_state)(void *state);
>> /* modeset, bracketing atomic_commit(): */
>> void (*prepare_fence)(struct msm_kms *kms,
>> struct drm_atomic_state *state);
>> @@ -114,7 +116,20 @@ struct msm_kms_funcs {
>> #endif
>> };
>>
>> +/**
>> + * Subclass of drm_private_state, to allow kms backend to have driver
>> + * private global state. The kms backend can do whatever it wants
>> + * with the ->state ptr.
>> + */
>> +struct msm_kms_state {
>> + struct drm_private_state base;
>> + void *state;
>> +};
>> +
>> struct msm_kms {
>> + struct drm_private_obj base;
>> + struct msm_kms_state state;
>> +
>> const struct msm_kms_funcs *funcs;
>>
>> /* irq number to be passed on to drm_irq_install */
>> @@ -124,18 +139,6 @@ struct msm_kms {
>> struct msm_gem_address_space *aspace;
>> };
>>
>> -/**
>> - * Subclass of drm_atomic_state, to allow kms backend to have driver
>> - * private global state. The kms backend can do whatever it wants
>> - * with the ->state ptr. On ->atomic_state_clear() the ->state ptr
>> - * is kfree'd and set back to NULL.
>> - */
>> -struct msm_kms_state {
>> - struct drm_atomic_state base;
>> - void *state;
>> -};
>> -#define to_kms_state(x) container_of(x, struct msm_kms_state, base)
>> -
>> static inline void msm_kms_init(struct msm_kms *kms,
>> const struct msm_kms_funcs *funcs)
>> {
>>
--
Jeykumar S
More information about the dri-devel
mailing list