* [PATCH] mmc: meson-gx: Convert host->lock to raw spinlock
@ 2026-09-21 19:13 Sean Anderson
2026-09-28 16:17 ` Ulf Hansson
0 siblings, 1 reply; 4+ messages in thread
From: Sean Anderson @ 2026-09-21 19:13 UTC (permalink / raw)
To: Ulf Hansson, linux-mmc
Cc: Martin Blumenstingl, Neil Armstrong, Kevin Hilman,
Heiner Kallweit, linux-arm-kernel, Jerome Brunet, linux-kernel,
linux-amlogic, Sean Anderson
The primary handler for IRQF_ONESHOT interrupts is always run without
threading, even on PREEMPT_RT. Therefore, we must use a raw spinlock,
which will never sleep (even on PREEMPT_RT).
Fixes: 066ecde6d826 ("mmc: meson-gx: add SDIO interrupt support")
Signed-off-by: Sean Anderson <sanderson@brivo.com>
---
drivers/mmc/host/meson-gx-mmc.c | 12 ++++++------
1 file changed, 6 insertions(+), 6 deletions(-)
diff --git a/drivers/mmc/host/meson-gx-mmc.c b/drivers/mmc/host/meson-gx-mmc.c
index 694bb443d5f3f..d5365c0404cb9 100644
--- a/drivers/mmc/host/meson-gx-mmc.c
+++ b/drivers/mmc/host/meson-gx-mmc.c
@@ -176,7 +176,7 @@ struct meson_host {
bool needs_pre_post_req;
- spinlock_t lock;
+ raw_spinlock_t lock;
};
#define CMD_CFG_LENGTH_MASK GENMASK(8, 0)
@@ -953,10 +953,10 @@ static irqreturn_t meson_mmc_irq(int irq, void *dev_id)
cmd = host->cmd;
if (status & IRQ_SDIO) {
- spin_lock(&host->lock);
+ raw_spin_lock(&host->lock);
__meson_mmc_enable_sdio_irq(host->mmc, 0);
sdio_signal_irq(host->mmc);
- spin_unlock(&host->lock);
+ raw_spin_unlock(&host->lock);
status &= ~IRQ_SDIO;
if (!status)
return IRQ_HANDLED;
@@ -1112,9 +1112,9 @@ static void meson_mmc_enable_sdio_irq(struct mmc_host *mmc, int enable)
struct meson_host *host = mmc_priv(mmc);
unsigned long flags;
- spin_lock_irqsave(&host->lock, flags);
+ raw_spin_lock_irqsave(&host->lock, flags);
__meson_mmc_enable_sdio_irq(mmc, enable);
- spin_unlock_irqrestore(&host->lock, flags);
+ raw_spin_unlock_irqrestore(&host->lock, flags);
}
static void meson_mmc_ack_sdio_irq(struct mmc_host *mmc)
@@ -1225,7 +1225,7 @@ static int meson_mmc_probe(struct platform_device *pdev)
if (ret)
goto err_init_clk;
- spin_lock_init(&host->lock);
+ raw_spin_lock_init(&host->lock);
if (host->dram_access_quirk) {
/* Limit segments to 1 due to low available sram memory */
---
base-commit: 587858367581b9c55c3690f4e63382ad622719d4
branch: meson_mmc_raw
--
2.53.0
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linux-amlogic@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-amlogic
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: [PATCH] mmc: meson-gx: Convert host->lock to raw spinlock
2026-09-21 19:13 [PATCH] mmc: meson-gx: Convert host->lock to raw spinlock Sean Anderson
@ 2026-09-28 16:17 ` Ulf Hansson
2026-09-28 16:22 ` Sean Anderson
0 siblings, 1 reply; 4+ messages in thread
From: Ulf Hansson @ 2026-09-28 16:17 UTC (permalink / raw)
To: Sean Anderson
Cc: Ulf Hansson, linux-mmc, Martin Blumenstingl, Neil Armstrong,
Kevin Hilman, Heiner Kallweit, linux-arm-kernel, Jerome Brunet,
linux-kernel, linux-amlogic
On Mon, Sep 21, 2026 at 9:14 PM Sean Anderson <sanderson@brivo.com> wrote:
>
> The primary handler for IRQF_ONESHOT interrupts is always run without
> threading, even on PREEMPT_RT. Therefore, we must use a raw spinlock,
> which will never sleep (even on PREEMPT_RT).
Sorry, but I don't quite understand the above. Are you saying that
IRQF_ONESHOT only works with raw spinlocks?
Kind regards
Uffe
>
> Fixes: 066ecde6d826 ("mmc: meson-gx: add SDIO interrupt support")
> Signed-off-by: Sean Anderson <sanderson@brivo.com>
> ---
>
> drivers/mmc/host/meson-gx-mmc.c | 12 ++++++------
> 1 file changed, 6 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/mmc/host/meson-gx-mmc.c b/drivers/mmc/host/meson-gx-mmc.c
> index 694bb443d5f3f..d5365c0404cb9 100644
> --- a/drivers/mmc/host/meson-gx-mmc.c
> +++ b/drivers/mmc/host/meson-gx-mmc.c
> @@ -176,7 +176,7 @@ struct meson_host {
>
> bool needs_pre_post_req;
>
> - spinlock_t lock;
> + raw_spinlock_t lock;
> };
>
> #define CMD_CFG_LENGTH_MASK GENMASK(8, 0)
> @@ -953,10 +953,10 @@ static irqreturn_t meson_mmc_irq(int irq, void *dev_id)
> cmd = host->cmd;
>
> if (status & IRQ_SDIO) {
> - spin_lock(&host->lock);
> + raw_spin_lock(&host->lock);
> __meson_mmc_enable_sdio_irq(host->mmc, 0);
> sdio_signal_irq(host->mmc);
> - spin_unlock(&host->lock);
> + raw_spin_unlock(&host->lock);
> status &= ~IRQ_SDIO;
> if (!status)
> return IRQ_HANDLED;
> @@ -1112,9 +1112,9 @@ static void meson_mmc_enable_sdio_irq(struct mmc_host *mmc, int enable)
> struct meson_host *host = mmc_priv(mmc);
> unsigned long flags;
>
> - spin_lock_irqsave(&host->lock, flags);
> + raw_spin_lock_irqsave(&host->lock, flags);
> __meson_mmc_enable_sdio_irq(mmc, enable);
> - spin_unlock_irqrestore(&host->lock, flags);
> + raw_spin_unlock_irqrestore(&host->lock, flags);
> }
>
> static void meson_mmc_ack_sdio_irq(struct mmc_host *mmc)
> @@ -1225,7 +1225,7 @@ static int meson_mmc_probe(struct platform_device *pdev)
> if (ret)
> goto err_init_clk;
>
> - spin_lock_init(&host->lock);
> + raw_spin_lock_init(&host->lock);
>
> if (host->dram_access_quirk) {
> /* Limit segments to 1 due to low available sram memory */
> ---
> base-commit: 587858367581b9c55c3690f4e63382ad622719d4
> branch: meson_mmc_raw
>
> --
> 2.53.0
>
_______________________________________________
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linux-amlogic@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-amlogic
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: [PATCH] mmc: meson-gx: Convert host->lock to raw spinlock
2026-09-28 16:17 ` Ulf Hansson
@ 2026-09-28 16:22 ` Sean Anderson
2026-09-30 9:27 ` Ulf Hansson
0 siblings, 1 reply; 4+ messages in thread
From: Sean Anderson @ 2026-09-28 16:22 UTC (permalink / raw)
To: Ulf Hansson
Cc: Ulf Hansson, linux-mmc, Martin Blumenstingl, Neil Armstrong,
Kevin Hilman, Heiner Kallweit, linux-arm-kernel, Jerome Brunet,
linux-kernel, linux-amlogic
On 9/28/26 12:17 PM, Ulf Hansson wrote:
> On Mon, Sep 21, 2026 at 9:14 PM Sean Anderson <sanderson@brivo.com> wrote:
>>
>> The primary handler for IRQF_ONESHOT interrupts is always run without
>> threading, even on PREEMPT_RT. Therefore, we must use a raw spinlock,
>> which will never sleep (even on PREEMPT_RT).
>
> Sorry, but I don't quite understand the above. Are you saying that
> IRQF_ONESHOT only works with raw spinlocks?
The primary handler of an IRQF_ONESHOT handler must use raw spinlocks.
https://www.kernel.org/doc/html/latest/core-api/real-time/differences.html#interrupt-handling
>
>>
>> Fixes: 066ecde6d826 ("mmc: meson-gx: add SDIO interrupt support")
>> Signed-off-by: Sean Anderson <sanderson@brivo.com>
>> ---
>>
>> drivers/mmc/host/meson-gx-mmc.c | 12 ++++++------
>> 1 file changed, 6 insertions(+), 6 deletions(-)
>>
>> diff --git a/drivers/mmc/host/meson-gx-mmc.c b/drivers/mmc/host/meson-gx-mmc.c
>> index 694bb443d5f3f..d5365c0404cb9 100644
>> --- a/drivers/mmc/host/meson-gx-mmc.c
>> +++ b/drivers/mmc/host/meson-gx-mmc.c
>> @@ -176,7 +176,7 @@ struct meson_host {
>>
>> bool needs_pre_post_req;
>>
>> - spinlock_t lock;
>> + raw_spinlock_t lock;
>> };
>>
>> #define CMD_CFG_LENGTH_MASK GENMASK(8, 0)
>> @@ -953,10 +953,10 @@ static irqreturn_t meson_mmc_irq(int irq, void *dev_id)
>> cmd = host->cmd;
>>
>> if (status & IRQ_SDIO) {
>> - spin_lock(&host->lock);
>> + raw_spin_lock(&host->lock);
>> __meson_mmc_enable_sdio_irq(host->mmc, 0);
>> sdio_signal_irq(host->mmc);
>> - spin_unlock(&host->lock);
>> + raw_spin_unlock(&host->lock);
>> status &= ~IRQ_SDIO;
>> if (!status)
>> return IRQ_HANDLED;
>> @@ -1112,9 +1112,9 @@ static void meson_mmc_enable_sdio_irq(struct mmc_host *mmc, int enable)
>> struct meson_host *host = mmc_priv(mmc);
>> unsigned long flags;
>>
>> - spin_lock_irqsave(&host->lock, flags);
>> + raw_spin_lock_irqsave(&host->lock, flags);
>> __meson_mmc_enable_sdio_irq(mmc, enable);
>> - spin_unlock_irqrestore(&host->lock, flags);
>> + raw_spin_unlock_irqrestore(&host->lock, flags);
>> }
>>
>> static void meson_mmc_ack_sdio_irq(struct mmc_host *mmc)
>> @@ -1225,7 +1225,7 @@ static int meson_mmc_probe(struct platform_device *pdev)
>> if (ret)
>> goto err_init_clk;
>>
>> - spin_lock_init(&host->lock);
>> + raw_spin_lock_init(&host->lock);
>>
>> if (host->dram_access_quirk) {
>> /* Limit segments to 1 due to low available sram memory */
>> ---
>> base-commit: 587858367581b9c55c3690f4e63382ad622719d4
>> branch: meson_mmc_raw
>>
>> --
>> 2.53.0
>>
_______________________________________________
linux-amlogic mailing list
linux-amlogic@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-amlogic
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: [PATCH] mmc: meson-gx: Convert host->lock to raw spinlock
2026-09-28 16:22 ` Sean Anderson
@ 2026-09-30 9:27 ` Ulf Hansson
0 siblings, 0 replies; 4+ messages in thread
From: Ulf Hansson @ 2026-09-30 9:27 UTC (permalink / raw)
To: Sean Anderson
Cc: Ulf Hansson, linux-mmc, Martin Blumenstingl, Neil Armstrong,
Kevin Hilman, Heiner Kallweit, linux-arm-kernel, Jerome Brunet,
linux-kernel, linux-amlogic
On Mon, Sep 28, 2026 at 6:22 PM Sean Anderson <sanderson@brivo.com> wrote:
>
>
>
> On 9/28/26 12:17 PM, Ulf Hansson wrote:
> > On Mon, Sep 21, 2026 at 9:14 PM Sean Anderson <sanderson@brivo.com> wrote:
> >>
> >> The primary handler for IRQF_ONESHOT interrupts is always run without
> >> threading, even on PREEMPT_RT. Therefore, we must use a raw spinlock,
> >> which will never sleep (even on PREEMPT_RT).
> >
> > Sorry, but I don't quite understand the above. Are you saying that
> > IRQF_ONESHOT only works with raw spinlocks?
>
> The primary handler of an IRQF_ONESHOT handler must use raw spinlocks.
>
> https://www.kernel.org/doc/html/latest/core-api/real-time/differences.html#interrupt-handling
Right, thanks for sharing!
Rather than moving to use a raw spinlock, I think a better option
would be to convert the driver into using only a threaded irq handler,
unless there are specific reasons why this can't work.
>
> >
> >>
> >> Fixes: 066ecde6d826 ("mmc: meson-gx: add SDIO interrupt support")
> >> Signed-off-by: Sean Anderson <sanderson@brivo.com>
Kind regards
Uffe
> >> ---
> >>
> >> drivers/mmc/host/meson-gx-mmc.c | 12 ++++++------
> >> 1 file changed, 6 insertions(+), 6 deletions(-)
> >>
> >> diff --git a/drivers/mmc/host/meson-gx-mmc.c b/drivers/mmc/host/meson-gx-mmc.c
> >> index 694bb443d5f3f..d5365c0404cb9 100644
> >> --- a/drivers/mmc/host/meson-gx-mmc.c
> >> +++ b/drivers/mmc/host/meson-gx-mmc.c
> >> @@ -176,7 +176,7 @@ struct meson_host {
> >>
> >> bool needs_pre_post_req;
> >>
> >> - spinlock_t lock;
> >> + raw_spinlock_t lock;
> >> };
> >>
> >> #define CMD_CFG_LENGTH_MASK GENMASK(8, 0)
> >> @@ -953,10 +953,10 @@ static irqreturn_t meson_mmc_irq(int irq, void *dev_id)
> >> cmd = host->cmd;
> >>
> >> if (status & IRQ_SDIO) {
> >> - spin_lock(&host->lock);
> >> + raw_spin_lock(&host->lock);
> >> __meson_mmc_enable_sdio_irq(host->mmc, 0);
> >> sdio_signal_irq(host->mmc);
> >> - spin_unlock(&host->lock);
> >> + raw_spin_unlock(&host->lock);
> >> status &= ~IRQ_SDIO;
> >> if (!status)
> >> return IRQ_HANDLED;
> >> @@ -1112,9 +1112,9 @@ static void meson_mmc_enable_sdio_irq(struct mmc_host *mmc, int enable)
> >> struct meson_host *host = mmc_priv(mmc);
> >> unsigned long flags;
> >>
> >> - spin_lock_irqsave(&host->lock, flags);
> >> + raw_spin_lock_irqsave(&host->lock, flags);
> >> __meson_mmc_enable_sdio_irq(mmc, enable);
> >> - spin_unlock_irqrestore(&host->lock, flags);
> >> + raw_spin_unlock_irqrestore(&host->lock, flags);
> >> }
> >>
> >> static void meson_mmc_ack_sdio_irq(struct mmc_host *mmc)
> >> @@ -1225,7 +1225,7 @@ static int meson_mmc_probe(struct platform_device *pdev)
> >> if (ret)
> >> goto err_init_clk;
> >>
> >> - spin_lock_init(&host->lock);
> >> + raw_spin_lock_init(&host->lock);
> >>
> >> if (host->dram_access_quirk) {
> >> /* Limit segments to 1 due to low available sram memory */
> >> ---
> >> base-commit: 587858367581b9c55c3690f4e63382ad622719d4
> >> branch: meson_mmc_raw
> >>
> >> --
> >> 2.53.0
> >>
>
_______________________________________________
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linux-amlogic@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-amlogic
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2026-09-30 9:28 UTC | newest]
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2026-09-21 19:13 [PATCH] mmc: meson-gx: Convert host->lock to raw spinlock Sean Anderson
2026-09-28 16:17 ` Ulf Hansson
2026-09-28 16:22 ` Sean Anderson
2026-09-30 9:27 ` Ulf Hansson
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