[PATCH] PCI: uniphier: Serialize INTx masking/unmasking

Subsystems: pci native host bridge and endpoint drivers, pci subsystem, pcie driver for socionext uniphier, the rest

STALE1813d

6 messages, 3 authors, 2021-08-26 · open the first message on its own page

[PATCH] PCI: uniphier: Serialize INTx masking/unmasking

From: Kunihiko Hayashi <hayashi.kunihiko@socionext.com>
Date: 2021-08-23 11:18:36 

The condition register PCI_RCV_INTX is used in irq_mask(), irq_unmask()
and irq_ack() callbacks. Accesses to register can occur at the same time
without a lock.
Add a lock into each callback to prevent the issue.

Fixes: 7e6d5cd88a6f ("PCI: uniphier: Add UniPhier PCIe host controller support")
Suggested-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Kunihiko Hayashi <hayashi.kunihiko@socionext.com>
---
 drivers/pci/controller/dwc/pcie-uniphier.c | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

The previous patch is as follows:
https://lore.kernel.org/linux-pci/1629370566-29984-1-git-send-email-hayashi.kunihiko@socionext.com/

Changes in the previous patch:
- Change the subject and commit message

diff --git a/drivers/pci/controller/dwc/pcie-uniphier.c b/drivers/pci/controller/dwc/pcie-uniphier.c
index ebe43e9..5075714 100644
--- a/drivers/pci/controller/dwc/pcie-uniphier.c
+++ b/drivers/pci/controller/dwc/pcie-uniphier.c
@@ -186,12 +186,17 @@ static void uniphier_pcie_irq_ack(struct irq_data *d)
 	struct pcie_port *pp = irq_data_get_irq_chip_data(d);
 	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
 	struct uniphier_pcie_priv *priv = to_uniphier_pcie(pci);
+	unsigned long flags;
 	u32 val;
 
+	raw_spin_lock_irqsave(&pp->lock, flags);
+
 	val = readl(priv->base + PCL_RCV_INTX);
 	val &= ~PCL_RCV_INTX_ALL_STATUS;
 	val |= BIT(irqd_to_hwirq(d) + PCL_RCV_INTX_STATUS_SHIFT);
 	writel(val, priv->base + PCL_RCV_INTX);
+
+	raw_spin_unlock_irqrestore(&pp->lock, flags);
 }
 
 static void uniphier_pcie_irq_mask(struct irq_data *d)
@@ -199,12 +204,17 @@ static void uniphier_pcie_irq_mask(struct irq_data *d)
 	struct pcie_port *pp = irq_data_get_irq_chip_data(d);
 	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
 	struct uniphier_pcie_priv *priv = to_uniphier_pcie(pci);
+	unsigned long flags;
 	u32 val;
 
+	raw_spin_lock_irqsave(&pp->lock, flags);
+
 	val = readl(priv->base + PCL_RCV_INTX);
 	val &= ~PCL_RCV_INTX_ALL_MASK;
 	val |= BIT(irqd_to_hwirq(d) + PCL_RCV_INTX_MASK_SHIFT);
 	writel(val, priv->base + PCL_RCV_INTX);
+
+	raw_spin_unlock_irqrestore(&pp->lock, flags);
 }
 
 static void uniphier_pcie_irq_unmask(struct irq_data *d)
@@ -212,12 +222,17 @@ static void uniphier_pcie_irq_unmask(struct irq_data *d)
 	struct pcie_port *pp = irq_data_get_irq_chip_data(d);
 	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
 	struct uniphier_pcie_priv *priv = to_uniphier_pcie(pci);
+	unsigned long flags;
 	u32 val;
 
+	raw_spin_lock_irqsave(&pp->lock, flags);
+
 	val = readl(priv->base + PCL_RCV_INTX);
 	val &= ~PCL_RCV_INTX_ALL_MASK;
 	val &= ~BIT(irqd_to_hwirq(d) + PCL_RCV_INTX_MASK_SHIFT);
 	writel(val, priv->base + PCL_RCV_INTX);
+
+	raw_spin_unlock_irqrestore(&pp->lock, flags);
 }
 
 static struct irq_chip uniphier_pcie_irq_chip = {
-- 
2.7.4


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Re: [PATCH] PCI: uniphier: Serialize INTx masking/unmasking

From: Pali Rohár <pali@kernel.org>
Date: 2021-08-23 15:09:35 

+ Marc (who originally reported this issue)

On Monday 23 August 2021 20:18:20 Kunihiko Hayashi wrote:
The condition register PCI_RCV_INTX is used in irq_mask(), irq_unmask()
and irq_ack() callbacks. Accesses to register can occur at the same time
without a lock.
Add a lock into each callback to prevent the issue.

Fixes: 7e6d5cd88a6f ("PCI: uniphier: Add UniPhier PCIe host controller support")
Suggested-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Kunihiko Hayashi <hayashi.kunihiko@socionext.com>
Acked-by: Pali Rohár <pali@kernel.org>
quoted hunk
---
 drivers/pci/controller/dwc/pcie-uniphier.c | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

The previous patch is as follows:
https://lore.kernel.org/linux-pci/1629370566-29984-1-git-send-email-hayashi.kunihiko@socionext.com/

Changes in the previous patch:
- Change the subject and commit message

diff --git a/drivers/pci/controller/dwc/pcie-uniphier.c b/drivers/pci/controller/dwc/pcie-uniphier.c
index ebe43e9..5075714 100644
--- a/drivers/pci/controller/dwc/pcie-uniphier.c
+++ b/drivers/pci/controller/dwc/pcie-uniphier.c
@@ -186,12 +186,17 @@ static void uniphier_pcie_irq_ack(struct irq_data *d)
 	struct pcie_port *pp = irq_data_get_irq_chip_data(d);
 	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
 	struct uniphier_pcie_priv *priv = to_uniphier_pcie(pci);
+	unsigned long flags;
 	u32 val;
 
+	raw_spin_lock_irqsave(&pp->lock, flags);
+
 	val = readl(priv->base + PCL_RCV_INTX);
 	val &= ~PCL_RCV_INTX_ALL_STATUS;
 	val |= BIT(irqd_to_hwirq(d) + PCL_RCV_INTX_STATUS_SHIFT);
 	writel(val, priv->base + PCL_RCV_INTX);
+
+	raw_spin_unlock_irqrestore(&pp->lock, flags);
 }
 
 static void uniphier_pcie_irq_mask(struct irq_data *d)
@@ -199,12 +204,17 @@ static void uniphier_pcie_irq_mask(struct irq_data *d)
 	struct pcie_port *pp = irq_data_get_irq_chip_data(d);
 	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
 	struct uniphier_pcie_priv *priv = to_uniphier_pcie(pci);
+	unsigned long flags;
 	u32 val;
 
+	raw_spin_lock_irqsave(&pp->lock, flags);
+
 	val = readl(priv->base + PCL_RCV_INTX);
 	val &= ~PCL_RCV_INTX_ALL_MASK;
 	val |= BIT(irqd_to_hwirq(d) + PCL_RCV_INTX_MASK_SHIFT);
 	writel(val, priv->base + PCL_RCV_INTX);
+
+	raw_spin_unlock_irqrestore(&pp->lock, flags);
 }
 
 static void uniphier_pcie_irq_unmask(struct irq_data *d)
@@ -212,12 +222,17 @@ static void uniphier_pcie_irq_unmask(struct irq_data *d)
 	struct pcie_port *pp = irq_data_get_irq_chip_data(d);
 	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
 	struct uniphier_pcie_priv *priv = to_uniphier_pcie(pci);
+	unsigned long flags;
 	u32 val;
 
+	raw_spin_lock_irqsave(&pp->lock, flags);
+
 	val = readl(priv->base + PCL_RCV_INTX);
 	val &= ~PCL_RCV_INTX_ALL_MASK;
 	val &= ~BIT(irqd_to_hwirq(d) + PCL_RCV_INTX_MASK_SHIFT);
 	writel(val, priv->base + PCL_RCV_INTX);
+
+	raw_spin_unlock_irqrestore(&pp->lock, flags);
 }
 
 static struct irq_chip uniphier_pcie_irq_chip = {
-- 
2.7.4
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Re: [PATCH] PCI: uniphier: Serialize INTx masking/unmasking

From: Marc Zyngier <maz@kernel.org>
Date: 2021-08-23 16:57:13 

On Mon, 23 Aug 2021 16:09:27 +0100,
Pali Rohár [off-list ref] wrote:
+ Marc (who originally reported this issue)

On Monday 23 August 2021 20:18:20 Kunihiko Hayashi wrote:
quoted
The condition register PCI_RCV_INTX is used in irq_mask(), irq_unmask()
and irq_ack() callbacks. Accesses to register can occur at the same time
without a lock.
Add a lock into each callback to prevent the issue.

Fixes: 7e6d5cd88a6f ("PCI: uniphier: Add UniPhier PCIe host controller support")
Suggested-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Kunihiko Hayashi <hayashi.kunihiko@socionext.com>
Acked-by: Pali Rohár <pali@kernel.org>
quoted
---
 drivers/pci/controller/dwc/pcie-uniphier.c | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

The previous patch is as follows:
https://lore.kernel.org/linux-pci/1629370566-29984-1-git-send-email-hayashi.kunihiko@socionext.com/

Changes in the previous patch:
- Change the subject and commit message

diff --git a/drivers/pci/controller/dwc/pcie-uniphier.c b/drivers/pci/controller/dwc/pcie-uniphier.c
index ebe43e9..5075714 100644
--- a/drivers/pci/controller/dwc/pcie-uniphier.c
+++ b/drivers/pci/controller/dwc/pcie-uniphier.c
@@ -186,12 +186,17 @@ static void uniphier_pcie_irq_ack(struct irq_data *d)
 	struct pcie_port *pp = irq_data_get_irq_chip_data(d);
 	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
 	struct uniphier_pcie_priv *priv = to_uniphier_pcie(pci);
+	unsigned long flags;
 	u32 val;
 
+	raw_spin_lock_irqsave(&pp->lock, flags);
+
 	val = readl(priv->base + PCL_RCV_INTX);
 	val &= ~PCL_RCV_INTX_ALL_STATUS;
 	val |= BIT(irqd_to_hwirq(d) + PCL_RCV_INTX_STATUS_SHIFT);
 	writel(val, priv->base + PCL_RCV_INTX);
+
+	raw_spin_unlock_irqrestore(&pp->lock, flags);
 }
 
 static void uniphier_pcie_irq_mask(struct irq_data *d)
@@ -199,12 +204,17 @@ static void uniphier_pcie_irq_mask(struct irq_data *d)
 	struct pcie_port *pp = irq_data_get_irq_chip_data(d);
 	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
 	struct uniphier_pcie_priv *priv = to_uniphier_pcie(pci);
+	unsigned long flags;
 	u32 val;
 
+	raw_spin_lock_irqsave(&pp->lock, flags);
+
 	val = readl(priv->base + PCL_RCV_INTX);
 	val &= ~PCL_RCV_INTX_ALL_MASK;
 	val |= BIT(irqd_to_hwirq(d) + PCL_RCV_INTX_MASK_SHIFT);
This looks extremely suspicious. You clear all the INTX mask bits, and
only set the one you need. How about the pre-existing bits?
quoted
 	writel(val, priv->base + PCL_RCV_INTX);
+
+	raw_spin_unlock_irqrestore(&pp->lock, flags);
 }
 
 static void uniphier_pcie_irq_unmask(struct irq_data *d)
@@ -212,12 +222,17 @@ static void uniphier_pcie_irq_unmask(struct irq_data *d)
 	struct pcie_port *pp = irq_data_get_irq_chip_data(d);
 	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
 	struct uniphier_pcie_priv *priv = to_uniphier_pcie(pci);
+	unsigned long flags;
 	u32 val;
 
+	raw_spin_lock_irqsave(&pp->lock, flags);
+
 	val = readl(priv->base + PCL_RCV_INTX);
 	val &= ~PCL_RCV_INTX_ALL_MASK;
 	val &= ~BIT(irqd_to_hwirq(d) + PCL_RCV_INTX_MASK_SHIFT);
And by the same token, this second line is totally useless.

I think masking/unmasking is broken in this driver, locking or not.

	M.

-- 
Without deviation from the norm, progress is not possible.

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Re: [PATCH] PCI: uniphier: Serialize INTx masking/unmasking

From: Kunihiko Hayashi <hayashi.kunihiko@socionext.com>
Date: 2021-08-25 00:01:13 

Hi Marc,

On 2021/08/24 1:57, Marc Zyngier wrote:
On Mon, 23 Aug 2021 16:09:27 +0100,
Pali Rohár [off-list ref] wrote:
quoted
+ Marc (who originally reported this issue)

On Monday 23 August 2021 20:18:20 Kunihiko Hayashi wrote:
quoted
The condition register PCI_RCV_INTX is used in irq_mask(), irq_unmask()
and irq_ack() callbacks. Accesses to register can occur at the same time
without a lock.
Add a lock into each callback to prevent the issue.

Fixes: 7e6d5cd88a6f ("PCI: uniphier: Add UniPhier PCIe host controller support")
Suggested-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Kunihiko Hayashi <hayashi.kunihiko@socionext.com>
Acked-by: Pali Rohár <pali@kernel.org>
quoted
---
  drivers/pci/controller/dwc/pcie-uniphier.c | 15 +++++++++++++++
  1 file changed, 15 insertions(+)

The previous patch is as follows:
https://lore.kernel.org/linux-pci/1629370566-29984-1-git-send-email-hayashi.kunihiko@socionext.com/

Changes in the previous patch:
- Change the subject and commit message

diff --git a/drivers/pci/controller/dwc/pcie-uniphier.c b/drivers/pci/controller/dwc/pcie-uniphier.c
index ebe43e9..5075714 100644
--- a/drivers/pci/controller/dwc/pcie-uniphier.c
+++ b/drivers/pci/controller/dwc/pcie-uniphier.c
@@ -186,12 +186,17 @@ static void uniphier_pcie_irq_ack(struct irq_data *d)
  	struct pcie_port *pp = irq_data_get_irq_chip_data(d);
  	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
  	struct uniphier_pcie_priv *priv = to_uniphier_pcie(pci);
+	unsigned long flags;
  	u32 val;
  
+	raw_spin_lock_irqsave(&pp->lock, flags);
+
  	val = readl(priv->base + PCL_RCV_INTX);
  	val &= ~PCL_RCV_INTX_ALL_STATUS;
  	val |= BIT(irqd_to_hwirq(d) + PCL_RCV_INTX_STATUS_SHIFT);
  	writel(val, priv->base + PCL_RCV_INTX);
+
+	raw_spin_unlock_irqrestore(&pp->lock, flags);
  }
  
  static void uniphier_pcie_irq_mask(struct irq_data *d)
@@ -199,12 +204,17 @@ static void uniphier_pcie_irq_mask(struct irq_data *d)
  	struct pcie_port *pp = irq_data_get_irq_chip_data(d);
  	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
  	struct uniphier_pcie_priv *priv = to_uniphier_pcie(pci);
+	unsigned long flags;
  	u32 val;
  
+	raw_spin_lock_irqsave(&pp->lock, flags);
+
  	val = readl(priv->base + PCL_RCV_INTX);
  	val &= ~PCL_RCV_INTX_ALL_MASK;
  	val |= BIT(irqd_to_hwirq(d) + PCL_RCV_INTX_MASK_SHIFT);
This looks extremely suspicious. You clear all the INTX mask bits, and
only set the one you need. How about the pre-existing bits?
Thanks for pointing out. No need to clear all INTX mask bits.
The pre-existing bits should be preserved.

quoted
quoted
  	writel(val, priv->base + PCL_RCV_INTX);
+
+	raw_spin_unlock_irqrestore(&pp->lock, flags);
  }
  
  static void uniphier_pcie_irq_unmask(struct irq_data *d)
@@ -212,12 +222,17 @@ static void uniphier_pcie_irq_unmask(struct irq_data *d)
  	struct pcie_port *pp = irq_data_get_irq_chip_data(d);
  	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
  	struct uniphier_pcie_priv *priv = to_uniphier_pcie(pci);
+	unsigned long flags;
  	u32 val;
  
+	raw_spin_lock_irqsave(&pp->lock, flags);
+
  	val = readl(priv->base + PCL_RCV_INTX);
  	val &= ~PCL_RCV_INTX_ALL_MASK;
  	val &= ~BIT(irqd_to_hwirq(d) + PCL_RCV_INTX_MASK_SHIFT);
And by the same token, this second line is totally useless.

I think masking/unmasking is broken in this driver, locking or not.
Yes, this second line should be removed, too.
I'll fix this bug and add mask locking.

Thank you,

---
Best Regards
Kunihiko Hayashi

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Re: [PATCH] PCI: uniphier: Serialize INTx masking/unmasking

    

      From: Marc Zyngier <maz@kernel.org>

      Date: 2021-08-25 09:07:13 
    

  

  
On Wed, 25 Aug 2021 01:01:08 +0100,
Kunihiko Hayashi [off-list ref] wrote:
Hi Marc,

On 2021/08/24 1:57, Marc Zyngier wrote:
quoted
On Mon, 23 Aug 2021 16:09:27 +0100,
Pali Rohár [off-list ref] wrote:
quoted
+ Marc (who originally reported this issue)

On Monday 23 August 2021 20:18:20 Kunihiko Hayashi wrote:
quoted
The condition register PCI_RCV_INTX is used in irq_mask(), irq_unmask()
and irq_ack() callbacks. Accesses to register can occur at the same time
without a lock.
Add a lock into each callback to prevent the issue.

Fixes: 7e6d5cd88a6f ("PCI: uniphier: Add UniPhier PCIe host controller support")
Suggested-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Kunihiko Hayashi <hayashi.kunihiko@socionext.com>
Acked-by: Pali Rohár <pali@kernel.org>

quoted
---
  drivers/pci/controller/dwc/pcie-uniphier.c | 15 +++++++++++++++
  1 file changed, 15 insertions(+)

The previous patch is as follows:
https://lore.kernel.org/linux-pci/1629370566-29984-1-git-send-email-hayashi.kunihiko@socionext.com/

Changes in the previous patch:
- Change the subject and commit message

diff --git a/drivers/pci/controller/dwc/pcie-uniphier.c b/drivers/pci/controller/dwc/pcie-uniphier.c
index ebe43e9..5075714 100644
--- a/drivers/pci/controller/dwc/pcie-uniphier.c
+++ b/drivers/pci/controller/dwc/pcie-uniphier.c
@@ -186,12 +186,17 @@ static void uniphier_pcie_irq_ack(struct irq_data *d)
  	struct pcie_port *pp = irq_data_get_irq_chip_data(d);
  	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
  	struct uniphier_pcie_priv *priv = to_uniphier_pcie(pci);
+	unsigned long flags;
  	u32 val;
  +	raw_spin_lock_irqsave(&pp->lock, flags);
+
  	val = readl(priv->base + PCL_RCV_INTX);
  	val &= ~PCL_RCV_INTX_ALL_STATUS;
  	val |= BIT(irqd_to_hwirq(d) + PCL_RCV_INTX_STATUS_SHIFT);
  	writel(val, priv->base + PCL_RCV_INTX);
+
+	raw_spin_unlock_irqrestore(&pp->lock, flags);
  }
    static void uniphier_pcie_irq_mask(struct irq_data *d)
@@ -199,12 +204,17 @@ static void uniphier_pcie_irq_mask(struct irq_data *d)
  	struct pcie_port *pp = irq_data_get_irq_chip_data(d);
  	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
  	struct uniphier_pcie_priv *priv = to_uniphier_pcie(pci);
+	unsigned long flags;
  	u32 val;
  +	raw_spin_lock_irqsave(&pp->lock, flags);
+
  	val = readl(priv->base + PCL_RCV_INTX);
  	val &= ~PCL_RCV_INTX_ALL_MASK;
  	val |= BIT(irqd_to_hwirq(d) + PCL_RCV_INTX_MASK_SHIFT);
This looks extremely suspicious. You clear all the INTX mask bits, and
only set the one you need. How about the pre-existing bits?
Thanks for pointing out. No need to clear all INTX mask bits.
The pre-existing bits should be preserved.

quoted
quoted
quoted
  	writel(val, priv->base + PCL_RCV_INTX);
+
+	raw_spin_unlock_irqrestore(&pp->lock, flags);
  }
    static void uniphier_pcie_irq_unmask(struct irq_data *d)
@@ -212,12 +222,17 @@ static void uniphier_pcie_irq_unmask(struct irq_data *d)
  	struct pcie_port *pp = irq_data_get_irq_chip_data(d);
  	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
  	struct uniphier_pcie_priv *priv = to_uniphier_pcie(pci);
+	unsigned long flags;
  	u32 val;
  +	raw_spin_lock_irqsave(&pp->lock, flags);
+
  	val = readl(priv->base + PCL_RCV_INTX);
  	val &= ~PCL_RCV_INTX_ALL_MASK;
  	val &= ~BIT(irqd_to_hwirq(d) + PCL_RCV_INTX_MASK_SHIFT);
And by the same token, this second line is totally useless.

I think masking/unmasking is broken in this driver, locking or not.
Yes, this second line should be removed, too.
You mean the *first* line, right? The one clearing all the INTx
bits. If you remove the second line, you won't fix anything.

Thanks,

	M.

-- 
Without deviation from the norm, progress is not possible.

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Re: [PATCH] PCI: uniphier: Serialize INTx masking/unmasking

    

      From: Kunihiko Hayashi <hayashi.kunihiko@socionext.com>

      Date: 2021-08-26 10:02:34 
    

  

  
Hi Marc,

On 2021/08/25 18:07, Marc Zyngier wrote:
On Wed, 25 Aug 2021 01:01:08 +0100,
Kunihiko Hayashi [off-list ref] wrote:
quoted
Hi Marc,

On 2021/08/24 1:57, Marc Zyngier wrote:
quoted
On Mon, 23 Aug 2021 16:09:27 +0100,
Pali Rohár [off-list ref] wrote:
quoted
+ Marc (who originally reported this issue)

On Monday 23 August 2021 20:18:20 Kunihiko Hayashi wrote:
quoted
The condition register PCI_RCV_INTX is used in irq_mask(), irq_unmask()
and irq_ack() callbacks. Accesses to register can occur at the same time
without a lock.
Add a lock into each callback to prevent the issue.

Fixes: 7e6d5cd88a6f ("PCI: uniphier: Add UniPhier PCIe host controller support")
Suggested-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Kunihiko Hayashi <hayashi.kunihiko@socionext.com>
Acked-by: Pali Rohár <pali@kernel.org>

quoted
---
   drivers/pci/controller/dwc/pcie-uniphier.c | 15 +++++++++++++++
   1 file changed, 15 insertions(+)

The previous patch is as follows:
https://lore.kernel.org/linux-pci/1629370566-29984-1-git-send-email-hayashi.kunihiko@socionext.com/

Changes in the previous patch:
- Change the subject and commit message

diff --git a/drivers/pci/controller/dwc/pcie-uniphier.c b/drivers/pci/controller/dwc/pcie-uniphier.c
index ebe43e9..5075714 100644
--- a/drivers/pci/controller/dwc/pcie-uniphier.c
+++ b/drivers/pci/controller/dwc/pcie-uniphier.c
@@ -186,12 +186,17 @@ static void uniphier_pcie_irq_ack(struct irq_data *d)
   	struct pcie_port *pp = irq_data_get_irq_chip_data(d);
   	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
   	struct uniphier_pcie_priv *priv = to_uniphier_pcie(pci);
+	unsigned long flags;
   	u32 val;
   +	raw_spin_lock_irqsave(&pp->lock, flags);
+
   	val = readl(priv->base + PCL_RCV_INTX);
   	val &= ~PCL_RCV_INTX_ALL_STATUS;
   	val |= BIT(irqd_to_hwirq(d) + PCL_RCV_INTX_STATUS_SHIFT);
   	writel(val, priv->base + PCL_RCV_INTX);
+
+	raw_spin_unlock_irqrestore(&pp->lock, flags);
   }
     static void uniphier_pcie_irq_mask(struct irq_data *d)
@@ -199,12 +204,17 @@ static void uniphier_pcie_irq_mask(struct irq_data *d)
   	struct pcie_port *pp = irq_data_get_irq_chip_data(d);
   	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
   	struct uniphier_pcie_priv *priv = to_uniphier_pcie(pci);
+	unsigned long flags;
   	u32 val;
   +	raw_spin_lock_irqsave(&pp->lock, flags);
+
   	val = readl(priv->base + PCL_RCV_INTX);
   	val &= ~PCL_RCV_INTX_ALL_MASK;
   	val |= BIT(irqd_to_hwirq(d) + PCL_RCV_INTX_MASK_SHIFT);
This looks extremely suspicious. You clear all the INTX mask bits, and
only set the one you need. How about the pre-existing bits?
Thanks for pointing out. No need to clear all INTX mask bits.
The pre-existing bits should be preserved.

quoted
quoted
quoted
   	writel(val, priv->base + PCL_RCV_INTX);
+
+	raw_spin_unlock_irqrestore(&pp->lock, flags);
   }
     static void uniphier_pcie_irq_unmask(struct irq_data *d)
@@ -212,12 +222,17 @@ static void uniphier_pcie_irq_unmask(struct irq_data *d)
   	struct pcie_port *pp = irq_data_get_irq_chip_data(d);
   	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
   	struct uniphier_pcie_priv *priv = to_uniphier_pcie(pci);
+	unsigned long flags;
   	u32 val;
   +	raw_spin_lock_irqsave(&pp->lock, flags);
+
   	val = readl(priv->base + PCL_RCV_INTX);
   	val &= ~PCL_RCV_INTX_ALL_MASK;
   	val &= ~BIT(irqd_to_hwirq(d) + PCL_RCV_INTX_MASK_SHIFT);
And by the same token, this second line is totally useless.

I think masking/unmasking is broken in this driver, locking or not.
Yes, this second line should be removed, too.
You mean the *first* line, right? The one clearing all the INTx
bits. If you remove the second line, you won't fix anything.
This is ambiguous. I mean that I will remove the following line:

     	val &= ~PCL_RCV_INTX_ALL_MASK;

So the fixed unmasking code is as follows.

     	val = readl(priv->base + PCL_RCV_INTX);
     	val &= ~BIT(irqd_to_hwirq(d) + PCL_RCV_INTX_STATUS_SHIFT);
     	writel(val, priv->base + PCL_RCV_INTX);

Thank you,

---
Best Regards
Kunihiko Hayashi

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