2020-11-06 01:58:09

by Tian Tao

Subject: [PATCH] mmc: dw_mmc: replace spin_lock_irqsave by spin_lock in hard IRQ

The code has been in a irq-disabled context since it is hard IRQ. There
is no necessity to do it again.

Signed-off-by: Tian Tao <[email protected]>
---
drivers/mmc/host/dw_mmc.c | 17 ++++++++---------
1 file changed, 8 insertions(+), 9 deletions(-)

diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c
index 43c5795..a524443 100644
--- a/drivers/mmc/host/dw_mmc.c
+++ b/drivers/mmc/host/dw_mmc.c
@@ -2617,7 +2617,6 @@ static irqreturn_t dw_mci_interrupt(int irq, void *dev_id)
struct dw_mci *host = dev_id;
u32 pending;
struct dw_mci_slot *slot = host->slot;
- unsigned long irqflags;

pending = mci_readl(host, MINTSTS); /* read-only mask reg */

@@ -2632,15 +2631,15 @@ static irqreturn_t dw_mci_interrupt(int irq, void *dev_id)
* Hold the lock; we know cmd11_timer can't be kicked
* off after the lock is released, so safe to delete.
*/
- spin_lock_irqsave(&host->irq_lock, irqflags);
+ spin_lock(&host->irq_lock);
dw_mci_cmd_interrupt(host, pending);
- spin_unlock_irqrestore(&host->irq_lock, irqflags);
+ spin_unlock(&host->irq_lock);

del_timer(&host->cmd11_timer);
}

if (pending & DW_MCI_CMD_ERROR_FLAGS) {
- spin_lock_irqsave(&host->irq_lock, irqflags);
+ spin_lock(&host->irq_lock);

del_timer(&host->cto_timer);
mci_writel(host, RINTSTS, DW_MCI_CMD_ERROR_FLAGS);
@@ -2648,7 +2647,7 @@ static irqreturn_t dw_mci_interrupt(int irq, void *dev_id)
smp_wmb(); /* drain writebuffer */
set_bit(EVENT_CMD_COMPLETE, &host->pending_events);

- spin_unlock_irqrestore(&host->irq_lock, irqflags);
+ spin_unlock(&host->irq_lock);
}

if (pending & DW_MCI_DATA_ERROR_FLAGS) {
@@ -2661,7 +2660,7 @@ static irqreturn_t dw_mci_interrupt(int irq, void *dev_id)
}

if (pending & SDMMC_INT_DATA_OVER) {
- spin_lock_irqsave(&host->irq_lock, irqflags);
+ spin_lock(&host->irq_lock);

del_timer(&host->dto_timer);

@@ -2676,7 +2675,7 @@ static irqreturn_t dw_mci_interrupt(int irq, void *dev_id)
set_bit(EVENT_DATA_COMPLETE, &host->pending_events);
tasklet_schedule(&host->tasklet);

- spin_unlock_irqrestore(&host->irq_lock, irqflags);
+ spin_unlock(&host->irq_lock);
}

if (pending & SDMMC_INT_RXDR) {
@@ -2692,12 +2691,12 @@ static irqreturn_t dw_mci_interrupt(int irq, void *dev_id)
}

if (pending & SDMMC_INT_CMD_DONE) {
- spin_lock_irqsave(&host->irq_lock, irqflags);
+ spin_lock(&host->irq_lock);

mci_writel(host, RINTSTS, SDMMC_INT_CMD_DONE);
dw_mci_cmd_interrupt(host, pending);

- spin_unlock_irqrestore(&host->irq_lock, irqflags);
+ spin_unlock(&host->irq_lock);
}

if (pending & SDMMC_INT_CD) {
--
2.7.4

2020-11-06 03:29:44

by Jaehoon Chung

Subject: Re: [PATCH] mmc: dw_mmc: replace spin_lock_irqsave by spin_lock in hard IRQ

Dear Tian,

On 11/6/20 10:56 AM, Tian Tao wrote:
> The code has been in a irq-disabled context since it is hard IRQ. There
> is no necessity to do it
Even though I don't remember, there is a reason to use spin_lock_irqsave()..
I will check it. If there is no reason, i will reply.

Best Regards,
Jaehoon Chung

>
> Signed-off-by: Tian Tao <[email protected]>
> ---
> drivers/mmc/host/dw_mmc.c | 17 ++++++++---------
> 1 file changed, 8 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c
> index 43c5795..a524443 100644
> --- a/drivers/mmc/host/dw_mmc.c
> +++ b/drivers/mmc/host/dw_mmc.c
> @@ -2617,7 +2617,6 @@ static irqreturn_t dw_mci_interrupt(int irq, void *dev_id)
> struct dw_mci *host = dev_id;
> u32 pending;
> struct dw_mci_slot *slot = host->slot;
> - unsigned long irqflags;
>
> pending = mci_readl(host, MINTSTS); /* read-only mask reg */
>
> @@ -2632,15 +2631,15 @@ static irqreturn_t dw_mci_interrupt(int irq, void *dev_id)
> * Hold the lock; we know cmd11_timer can't be kicked
> * off after the lock is released, so safe to delete.
> */
> - spin_lock_irqsave(&host->irq_lock, irqflags);
> + spin_lock(&host->irq_lock);
> dw_mci_cmd_interrupt(host, pending);
> - spin_unlock_irqrestore(&host->irq_lock, irqflags);
> + spin_unlock(&host->irq_lock);
>
> del_timer(&host->cmd11_timer);
> }
>
> if (pending & DW_MCI_CMD_ERROR_FLAGS) {
> - spin_lock_irqsave(&host->irq_lock, irqflags);
> + spin_lock(&host->irq_lock);
>
> del_timer(&host->cto_timer);
> mci_writel(host, RINTSTS, DW_MCI_CMD_ERROR_FLAGS);
> @@ -2648,7 +2647,7 @@ static irqreturn_t dw_mci_interrupt(int irq, void *dev_id)
> smp_wmb(); /* drain writebuffer */
> set_bit(EVENT_CMD_COMPLETE, &host->pending_events);
>
> - spin_unlock_irqrestore(&host->irq_lock, irqflags);
> + spin_unlock(&host->irq_lock);
> }
>
> if (pending & DW_MCI_DATA_ERROR_FLAGS) {
> @@ -2661,7 +2660,7 @@ static irqreturn_t dw_mci_interrupt(int irq, void *dev_id)
> }
>
> if (pending & SDMMC_INT_DATA_OVER) {
> - spin_lock_irqsave(&host->irq_lock, irqflags);
> + spin_lock(&host->irq_lock);
>
> del_timer(&host->dto_timer);
>
> @@ -2676,7 +2675,7 @@ static irqreturn_t dw_mci_interrupt(int irq, void *dev_id)
> set_bit(EVENT_DATA_COMPLETE, &host->pending_events);
> tasklet_schedule(&host->tasklet);
>
> - spin_unlock_irqrestore(&host->irq_lock, irqflags);
> + spin_unlock(&host->irq_lock);
> }
>
> if (pending & SDMMC_INT_RXDR) {
> @@ -2692,12 +2691,12 @@ static irqreturn_t dw_mci_interrupt(int irq, void *dev_id)
> }
>
> if (pending & SDMMC_INT_CMD_DONE) {
> - spin_lock_irqsave(&host->irq_lock, irqflags);
> + spin_lock(&host->irq_lock);
>
> mci_writel(host, RINTSTS, SDMMC_INT_CMD_DONE);
> dw_mci_cmd_interrupt(host, pending);
>
> - spin_unlock_irqrestore(&host->irq_lock, irqflags);
> + spin_unlock(&host->irq_lock);
> }
>
> if (pending & SDMMC_INT_CD) {
>

2020-11-10 12:28:37

by Ulf Hansson

Subject: Re: [PATCH] mmc: dw_mmc: replace spin_lock_irqsave by spin_lock in hard IRQ

On Fri, 6 Nov 2020 at 02:56, Tian Tao <[email protected]> wrote:
>
> The code has been in a irq-disabled context since it is hard IRQ. There
> is no necessity to do it again.
>
> Signed-off-by: Tian Tao <[email protected]>

Applied for next, thanks!

Kind regards
Uffe


> ---
> drivers/mmc/host/dw_mmc.c | 17 ++++++++---------
> 1 file changed, 8 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c
> index 43c5795..a524443 100644
> --- a/drivers/mmc/host/dw_mmc.c
> +++ b/drivers/mmc/host/dw_mmc.c
> @@ -2617,7 +2617,6 @@ static irqreturn_t dw_mci_interrupt(int irq, void *dev_id)
> struct dw_mci *host = dev_id;
> u32 pending;
> struct dw_mci_slot *slot = host->slot;
> - unsigned long irqflags;
>
> pending = mci_readl(host, MINTSTS); /* read-only mask reg */
>
> @@ -2632,15 +2631,15 @@ static irqreturn_t dw_mci_interrupt(int irq, void *dev_id)
> * Hold the lock; we know cmd11_timer can't be kicked
> * off after the lock is released, so safe to delete.
> */
> - spin_lock_irqsave(&host->irq_lock, irqflags);
> + spin_lock(&host->irq_lock);
> dw_mci_cmd_interrupt(host, pending);
> - spin_unlock_irqrestore(&host->irq_lock, irqflags);
> + spin_unlock(&host->irq_lock);
>
> del_timer(&host->cmd11_timer);
> }
>
> if (pending & DW_MCI_CMD_ERROR_FLAGS) {
> - spin_lock_irqsave(&host->irq_lock, irqflags);
> + spin_lock(&host->irq_lock);
>
> del_timer(&host->cto_timer);
> mci_writel(host, RINTSTS, DW_MCI_CMD_ERROR_FLAGS);
> @@ -2648,7 +2647,7 @@ static irqreturn_t dw_mci_interrupt(int irq, void *dev_id)
> smp_wmb(); /* drain writebuffer */
> set_bit(EVENT_CMD_COMPLETE, &host->pending_events);
>
> - spin_unlock_irqrestore(&host->irq_lock, irqflags);
> + spin_unlock(&host->irq_lock);
> }
>
> if (pending & DW_MCI_DATA_ERROR_FLAGS) {
> @@ -2661,7 +2660,7 @@ static irqreturn_t dw_mci_interrupt(int irq, void *dev_id)
> }
>
> if (pending & SDMMC_INT_DATA_OVER) {
> - spin_lock_irqsave(&host->irq_lock, irqflags);
> + spin_lock(&host->irq_lock);
>
> del_timer(&host->dto_timer);
>
> @@ -2676,7 +2675,7 @@ static irqreturn_t dw_mci_interrupt(int irq, void *dev_id)
> set_bit(EVENT_DATA_COMPLETE, &host->pending_events);
> tasklet_schedule(&host->tasklet);
>
> - spin_unlock_irqrestore(&host->irq_lock, irqflags);
> + spin_unlock(&host->irq_lock);
> }
>
> if (pending & SDMMC_INT_RXDR) {
> @@ -2692,12 +2691,12 @@ static irqreturn_t dw_mci_interrupt(int irq, void *dev_id)
> }
>
> if (pending & SDMMC_INT_CMD_DONE) {
> - spin_lock_irqsave(&host->irq_lock, irqflags);
> + spin_lock(&host->irq_lock);
>
> mci_writel(host, RINTSTS, SDMMC_INT_CMD_DONE);
> dw_mci_cmd_interrupt(host, pending);
>
> - spin_unlock_irqrestore(&host->irq_lock, irqflags);
> + spin_unlock(&host->irq_lock);
> }
>
> if (pending & SDMMC_INT_CD) {
> --
> 2.7.4
>