From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id E4B6D1A840A for ; Fri, 9 Jan 2026 16:05:10 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1767974713; cv=none; b=ivT2H+FKCN4aDyPaAWtc+sJArmhKVpca879Nv5zixajUnCXEVnBY+SjBqe1el4egL00DkjC0+P9JLMS/Helya4AL1614uLNq3eh2LnGH/qx/6sLeOL9YbUM4DKY6VKpMybPAzYjKAAV9vh6ixClWRKO20nDMVsy8HIR5kmJv/DQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1767974713; c=relaxed/simple; bh=WSFqugOisgK1mqmHFdj8h7dOO3HjAVcFKLMxtEYwgns=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=uYYNLRbujioJov9GhDop7XRZLIMcQqj7qio4X/fejBmUtuAODi8bGX4MemLuhUAfdYzcURu3prR+LlcvtDQfusWHw2vJ94p5l8TuWoF6fVSz6Fj3YM6SUvRkDVnybo7JbqEgL5vKbnjfef5UN8RkdY8L+Jv3PVH2d2Ohix7jpU4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 4AA1B497; Fri, 9 Jan 2026 08:05:03 -0800 (PST) Received: from [10.1.36.18] (e122027.cambridge.arm.com [10.1.36.18]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id A7CB13F5A1; Fri, 9 Jan 2026 08:05:07 -0800 (PST) Message-ID: <67b943c4-ec28-4d14-bb34-34efabeb5360@arm.com> Date: Fri, 9 Jan 2026 16:05:05 +0000 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v7 2/4] drm/panthor: Rework panthor_irq::suspended into panthor_irq::state To: Nicolas Frattaroli , Boris Brezillon , Liviu Dudau , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , David Airlie , Simona Vetter , Chia-I Wu , Karunika Choo Cc: kernel@collabora.com, linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org References: <20260108-panthor-tracepoints-v7-0-afeae181f74a@collabora.com> <20260108-panthor-tracepoints-v7-2-afeae181f74a@collabora.com> From: Steven Price Content-Language: en-GB In-Reply-To: <20260108-panthor-tracepoints-v7-2-afeae181f74a@collabora.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 08/01/2026 14:19, Nicolas Frattaroli wrote: > 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 > --- > 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) \ Do we want to also catch the STATE_SUSPENDING case here? AFAICT in SUSPENDING we should be confident that _INT_MASK==0 so this shouldn't a problem (_INT_STAT should read as 0 below). But we don't want interrupts during STATE_SUSPENDING so we might as well handle it. Thanks, Steve > 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); \ > } > >