diff options
author | AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com> | 2023-12-04 12:42:15 +0100 |
---|---|---|
committer | Boris Brezillon <boris.brezillon@collabora.com> | 2023-12-05 11:39:59 +0100 |
commit | 157ad4ccff0754d9eb57d3a4fa31264ee6e9716b (patch) | |
tree | 176949e7457bcf2a3a3cd91f416330410d1dc812 /drivers/gpu/drm/panfrost/panfrost_mmu.c | |
parent | b98e9a84d38ac88f9fd2accbcd45b656eeea7a04 (diff) |
drm/panfrost: Synchronize and disable interrupts before powering off
To make sure that we don't unintentionally perform any unclocked and/or
unpowered R/W operation on GPU registers, before turning off clocks and
regulators we must make sure that no GPU, JOB or MMU ISR execution is
pending: doing that requires to add a mechanism to synchronize the
interrupts on suspend.
Add functions panfrost_{gpu,job,mmu}_suspend_irq() which will perform
interrupts masking and ISR execution synchronization, and then call
those in the panfrost_device_runtime_suspend() handler in the exact
sequence of job (may require mmu!) -> mmu -> gpu.
As a side note, JOB and MMU suspend_irq functions needed some special
treatment: as their interrupt handlers will unmask interrupts, it was
necessary to add an `is_suspended` bitmap which is used to address the
possible corner case of unintentional IRQ unmasking because of ISR
execution after a call to synchronize_irq().
At resume, clear each is_suspended bit in the reset path of JOB/MMU
to allow unmasking the interrupts.
Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com>
Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>
Reviewed-by: Steven Price <steven.price@arm.com>
Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231204114215.54575-4-angelogioacchino.delregno@collabora.com
Diffstat (limited to 'drivers/gpu/drm/panfrost/panfrost_mmu.c')
-rw-r--r-- | drivers/gpu/drm/panfrost/panfrost_mmu.c | 22 |
1 files changed, 19 insertions, 3 deletions
diff --git a/drivers/gpu/drm/panfrost/panfrost_mmu.c b/drivers/gpu/drm/panfrost/panfrost_mmu.c index ac4296c1e54b..f38385fe76bb 100644 --- a/drivers/gpu/drm/panfrost/panfrost_mmu.c +++ b/drivers/gpu/drm/panfrost/panfrost_mmu.c @@ -231,6 +231,8 @@ void panfrost_mmu_reset(struct panfrost_device *pfdev) { struct panfrost_mmu *mmu, *mmu_tmp; + clear_bit(PANFROST_COMP_BIT_MMU, pfdev->is_suspended); + spin_lock(&pfdev->as_lock); pfdev->as_alloc_mask = 0; @@ -670,6 +672,9 @@ static irqreturn_t panfrost_mmu_irq_handler(int irq, void *data) { struct panfrost_device *pfdev = data; + if (test_bit(PANFROST_COMP_BIT_MMU, pfdev->is_suspended)) + return IRQ_NONE; + if (!mmu_read(pfdev, MMU_INT_STAT)) return IRQ_NONE; @@ -744,9 +749,12 @@ static irqreturn_t panfrost_mmu_irq_handler_thread(int irq, void *data) status = mmu_read(pfdev, MMU_INT_RAWSTAT) & ~pfdev->as_faulty_mask; } - spin_lock(&pfdev->as_lock); - mmu_write(pfdev, MMU_INT_MASK, ~pfdev->as_faulty_mask); - spin_unlock(&pfdev->as_lock); + /* Enable interrupts only if we're not about to get suspended */ + if (!test_bit(PANFROST_COMP_BIT_MMU, pfdev->is_suspended)) { + spin_lock(&pfdev->as_lock); + mmu_write(pfdev, MMU_INT_MASK, ~pfdev->as_faulty_mask); + spin_unlock(&pfdev->as_lock); + } return IRQ_HANDLED; }; @@ -777,3 +785,11 @@ void panfrost_mmu_fini(struct panfrost_device *pfdev) { mmu_write(pfdev, MMU_INT_MASK, 0); } + +void panfrost_mmu_suspend_irq(struct panfrost_device *pfdev) +{ + set_bit(PANFROST_COMP_BIT_MMU, pfdev->is_suspended); + + mmu_write(pfdev, MMU_INT_MASK, 0); + synchronize_irq(pfdev->mmu_irq); +} |