To deal with the threaded interrupt handler and a suspend action
overlapping, the boolean panthor_irq::suspended is not sufficient.

Rework it into taking several different values depending on the current
state, and check it and set it within the IRQ helper functions.

Signed-off-by: Nicolas Frattaroli <[email protected]>
---
 drivers/gpu/drm/panthor/panthor_device.h | 40 +++++++++++++++++++++++++-------
 1 file changed, 32 insertions(+), 8 deletions(-)

diff --git a/drivers/gpu/drm/panthor/panthor_device.h 
b/drivers/gpu/drm/panthor/panthor_device.h
index cf76a8abca76..a8c21a7eea05 100644
--- a/drivers/gpu/drm/panthor/panthor_device.h
+++ b/drivers/gpu/drm/panthor/panthor_device.h
@@ -61,6 +61,17 @@ enum panthor_device_pm_state {
        PANTHOR_DEVICE_PM_STATE_SUSPENDING,
 };
 
+enum panthor_irq_state {
+       /** @PANTHOR_IRQ_STATE_ACTIVE: IRQ is active and ready to process 
events. */
+       PANTHOR_IRQ_STATE_ACTIVE = 0,
+       /** @PANTHOR_IRQ_STATE_PROCESSING: IRQ is currently processing events. 
*/
+       PANTHOR_IRQ_STATE_PROCESSING,
+       /** @PANTHOR_IRQ_STATE_SUSPENDED: IRQ is suspended. */
+       PANTHOR_IRQ_STATE_SUSPENDED,
+       /** @PANTHOR_IRQ_STATE_SUSPENDING: IRQ is being suspended. */
+       PANTHOR_IRQ_STATE_SUSPENDING,
+};
+
 /**
  * struct panthor_irq - IRQ data
  *
@@ -76,8 +87,8 @@ struct panthor_irq {
        /** @mask: Values to write to xxx_INT_MASK if active. */
        u32 mask;
 
-       /** @suspended: Set to true when the IRQ is suspended. */
-       atomic_t suspended;
+       /** @state: one of &enum panthor_irq_state reflecting the current 
state. */
+       atomic_t state;
 
        /** @mask_lock: protects modifications to _INT_MASK and @mask */
        spinlock_t mask_lock;
@@ -415,7 +426,7 @@ static irqreturn_t panthor_ ## __name ## 
_irq_raw_handler(int irq, void *data)
                                                                                
                \
        guard(spinlock_irqsave)(&pirq->mask_lock);                              
                \
                                                                                
                \
-       if (atomic_read(&pirq->suspended))                                      
                \
+       if (atomic_read(&pirq->state) == PANTHOR_IRQ_STATE_SUSPENDED)           
                \
                return IRQ_NONE;                                                
                \
        if (!gpu_read(ptdev, __reg_prefix ## _INT_STAT))                        
                \
                return IRQ_NONE;                                                
                \
@@ -428,11 +439,14 @@ static irqreturn_t panthor_ ## __name ## 
_irq_threaded_handler(int irq, void *da
 {                                                                              
                \
        struct panthor_irq *pirq = data;                                        
                \
        struct panthor_device *ptdev = pirq->ptdev;                             
                \
+       enum panthor_irq_state state;                                           
                \
        irqreturn_t ret = IRQ_NONE;                                             
                \
        u32 mask;                                                               
                \
                                                                                
                \
        scoped_guard(spinlock_irqsave, &pirq->mask_lock) {                      
                \
                mask = pirq->mask;                                              
                \
+               atomic_cmpxchg(&pirq->state, PANTHOR_IRQ_STATE_ACTIVE,          
                \
+                              PANTHOR_IRQ_STATE_PROCESSING);                   
                \
        }                                                                       
                \
                                                                                
                \
        while (true) {                                                          
                \
@@ -446,11 +460,14 @@ static irqreturn_t panthor_ ## __name ## 
_irq_threaded_handler(int irq, void *da
        }                                                                       
                \
                                                                                
                \
        scoped_guard(spinlock_irqsave, &pirq->mask_lock) {                      
                \
-               if (!atomic_read(&pirq->suspended)) {                           
                \
+               state = atomic_read(&pirq->state);                              
                \
+               if (state != PANTHOR_IRQ_STATE_SUSPENDED &&                     
                \
+                   state != PANTHOR_IRQ_STATE_SUSPENDING) {                    
                \
                        /* Only restore the bits that were used and are still 
enabled */        \
                        gpu_write(ptdev, __reg_prefix ## _INT_MASK,             
                \
                                  gpu_read(ptdev, __reg_prefix ## _INT_MASK) |  
                \
                                  (mask & pirq->mask));                         
                \
+                       atomic_set(&pirq->state, PANTHOR_IRQ_STATE_ACTIVE);     
                \
                }                                                               
                \
        }                                                                       
                \
                                                                                
                \
@@ -461,16 +478,17 @@ static inline void panthor_ ## __name ## 
_irq_suspend(struct panthor_irq *pirq)
 {                                                                              
                \
        scoped_guard(spinlock_irqsave, &pirq->mask_lock) {                      
                \
                gpu_write(pirq->ptdev, __reg_prefix ## _INT_MASK, 0);           
                \
+               atomic_set(&pirq->state, PANTHOR_IRQ_STATE_SUSPENDING);         
                \
        }                                                                       
                \
        synchronize_irq(pirq->irq);                                             
                \
-       atomic_set(&pirq->suspended, true);                                     
                \
+       atomic_set(&pirq->state, PANTHOR_IRQ_STATE_SUSPENDED);                  
                \
 }                                                                              
                \
                                                                                
                \
 static inline void panthor_ ## __name ## _irq_resume(struct panthor_irq *pirq) 
                \
 {                                                                              
                \
        guard(spinlock_irqsave)(&pirq->mask_lock);                              
                \
                                                                                
                \
-       atomic_set(&pirq->suspended, false);                                    
                \
+       atomic_set(&pirq->state, PANTHOR_IRQ_STATE_ACTIVE);                     
                \
        gpu_write(pirq->ptdev, __reg_prefix ## _INT_CLEAR, pirq->mask);         
                \
        gpu_write(pirq->ptdev, __reg_prefix ## _INT_MASK, pirq->mask);          
                \
 }                                                                              
                \
@@ -494,19 +512,25 @@ static int panthor_request_ ## __name ## _irq(struct 
panthor_device *ptdev,                       \
                                                                                
                \
 static inline void panthor_ ## __name ## _irq_enable_events(struct panthor_irq 
*pirq, u32 mask)        \
 {                                                                              
                \
+       enum panthor_irq_state state;                                           
                \
+                                                                               
                \
        guard(spinlock_irqsave)(&pirq->mask_lock);                              
                \
                                                                                
                \
        pirq->mask |= mask;                                                     
                \
-       if (!atomic_read(&pirq->suspended))                                     
                \
+       state = atomic_read(&pirq->state);                                      
                \
+       if (state != PANTHOR_IRQ_STATE_SUSPENDED && state != 
PANTHOR_IRQ_STATE_SUSPENDING)      \
                gpu_write(pirq->ptdev, __reg_prefix ## _INT_MASK, pirq->mask);  
                \
 }                                                                              
                \
                                                                                
                \
 static inline void panthor_ ## __name ## _irq_disable_events(struct 
panthor_irq *pirq, u32 mask)\
 {                                                                              
                \
+       enum panthor_irq_state state;                                           
                \
+                                                                               
                \
        guard(spinlock_irqsave)(&pirq->mask_lock);                              
                \
                                                                                
                \
        pirq->mask &= ~mask;                                                    
                \
-       if (!atomic_read(&pirq->suspended))                                     
                \
+       state = atomic_read(&pirq->state);                                      
                \
+       if (state != PANTHOR_IRQ_STATE_SUSPENDED && state != 
PANTHOR_IRQ_STATE_SUSPENDING)      \
                gpu_write(pirq->ptdev, __reg_prefix ## _INT_MASK, pirq->mask);  
                \
 }
 

-- 
2.52.0

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