[PATCH V2] simplify init function

[PATCH V2] simplify init function

[Tomas Henzl]

by removing few lines. No functional change.

Signed-off-by: Tomas Henzl <thenzl@redhat.com>
---
V2: ahci_init_irq is now a void function

 drivers/ata/ahci.c | 23 ++++++++++++-----------
 1 file changed, 12 insertions(+), 11 deletions(-)

diff --git a/drivers/ata/ahci.c b/drivers/ata/ahci.c
index 8d27c567be1c..3ea2f3adf354 100644
--- a/drivers/ata/ahci.c
+++ b/drivers/ata/ahci.c
@@ -1665,13 +1665,15 @@ static int ahci_get_irq_vector(struct ata_host *host, int port)
 	return pci_irq_vector(to_pci_dev(host->dev), port);
 }
 
-static int ahci_init_msi(struct pci_dev *pdev, unsigned int n_ports,
+static void ahci_init_irq(struct pci_dev *pdev, unsigned int n_ports,
 			struct ahci_host_priv *hpriv)
 {
 	int nvec;
 
-	if (hpriv->flags & AHCI_HFLAG_NO_MSI)
-		return -ENODEV;
+	if (hpriv->flags & AHCI_HFLAG_NO_MSI) {
+		pci_alloc_irq_vectors(pdev, 1, 1, PCI_IRQ_INTX);
+		return;
+	}
 
 	/*
 	 * If number of MSIs is less than number of ports then Sharing Last
@@ -1685,7 +1687,7 @@ static int ahci_init_msi(struct pci_dev *pdev, unsigned int n_ports,
 			if (!(readl(hpriv->mmio + HOST_CTL) & HOST_MRSM)) {
 				hpriv->get_irq_vector = ahci_get_irq_vector;
 				hpriv->flags |= AHCI_HFLAG_MULTI_MSI;
-				return nvec;
+				return;
 			}
 
 			/*
@@ -1700,12 +1702,13 @@ static int ahci_init_msi(struct pci_dev *pdev, unsigned int n_ports,
 
 	/*
 	 * If the host is not capable of supporting per-port vectors, fall
-	 * back to single MSI before finally attempting single MSI-X.
+	 * back to single MSI before finally attempting single MSI-X or
+	 * a legacy INTx.
 	 */
 	nvec = pci_alloc_irq_vectors(pdev, 1, 1, PCI_IRQ_MSI);
 	if (nvec == 1)
-		return nvec;
-	return pci_alloc_irq_vectors(pdev, 1, 1, PCI_IRQ_MSIX);
+		return;
+	pci_alloc_irq_vectors(pdev, 1, 1, PCI_IRQ_MSIX | PCI_IRQ_INTX);
 }
 
 static void ahci_mark_external_port(struct ata_port *ap)
@@ -1985,10 +1988,8 @@ static int ahci_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
 	}
 	host->private_data = hpriv;
 
-	if (ahci_init_msi(pdev, n_ports, hpriv) < 0) {
-		/* legacy intx interrupts */
-		pci_intx(pdev, 1);
-	}
+	ahci_init_irq(pdev, n_ports, hpriv);
+
 	hpriv->irq = pci_irq_vector(pdev, 0);
 
 	if (!(hpriv->cap & HOST_CAP_SSS) || ahci_ignore_sss)
-- 
2.47.1

Re: [PATCH V2] simplify init function

[Damien Le Moal]

On 1/14/25 01:34, Tomas Henzl wrote:
> by removing few lines. No functional change.

Looks OK to me, but:

The patch title should be: "ata: ahci: simplify init function"

And the commit message should also describe why it is OK to change
ahci_init_irq() to be a void function. Can you send a V3 with that addressed
please ?

> 
> Signed-off-by: Tomas Henzl <thenzl@redhat.com>
> ---
> V2: ahci_init_irq is now a void function
> 
>  drivers/ata/ahci.c | 23 ++++++++++++-----------
>  1 file changed, 12 insertions(+), 11 deletions(-)
> 
> diff --git a/drivers/ata/ahci.c b/drivers/ata/ahci.c
> index 8d27c567be1c..3ea2f3adf354 100644
> --- a/drivers/ata/ahci.c
> +++ b/drivers/ata/ahci.c
> @@ -1665,13 +1665,15 @@ static int ahci_get_irq_vector(struct ata_host *host, int port)
>  	return pci_irq_vector(to_pci_dev(host->dev), port);
>  }
>  
> -static int ahci_init_msi(struct pci_dev *pdev, unsigned int n_ports,
> +static void ahci_init_irq(struct pci_dev *pdev, unsigned int n_ports,
>  			struct ahci_host_priv *hpriv)
>  {
>  	int nvec;
>  
> -	if (hpriv->flags & AHCI_HFLAG_NO_MSI)
> -		return -ENODEV;
> +	if (hpriv->flags & AHCI_HFLAG_NO_MSI) {
> +		pci_alloc_irq_vectors(pdev, 1, 1, PCI_IRQ_INTX);
> +		return;
> +	}
>  
>  	/*
>  	 * If number of MSIs is less than number of ports then Sharing Last
> @@ -1685,7 +1687,7 @@ static int ahci_init_msi(struct pci_dev *pdev, unsigned int n_ports,
>  			if (!(readl(hpriv->mmio + HOST_CTL) & HOST_MRSM)) {
>  				hpriv->get_irq_vector = ahci_get_irq_vector;
>  				hpriv->flags |= AHCI_HFLAG_MULTI_MSI;
> -				return nvec;
> +				return;
>  			}
>  
>  			/*
> @@ -1700,12 +1702,13 @@ static int ahci_init_msi(struct pci_dev *pdev, unsigned int n_ports,
>  
>  	/*
>  	 * If the host is not capable of supporting per-port vectors, fall
> -	 * back to single MSI before finally attempting single MSI-X.
> +	 * back to single MSI before finally attempting single MSI-X or
> +	 * a legacy INTx.
>  	 */
>  	nvec = pci_alloc_irq_vectors(pdev, 1, 1, PCI_IRQ_MSI);
>  	if (nvec == 1)
> -		return nvec;
> -	return pci_alloc_irq_vectors(pdev, 1, 1, PCI_IRQ_MSIX);
> +		return;
> +	pci_alloc_irq_vectors(pdev, 1, 1, PCI_IRQ_MSIX | PCI_IRQ_INTX);
>  }
>  
>  static void ahci_mark_external_port(struct ata_port *ap)
> @@ -1985,10 +1988,8 @@ static int ahci_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
>  	}
>  	host->private_data = hpriv;
>  
> -	if (ahci_init_msi(pdev, n_ports, hpriv) < 0) {
> -		/* legacy intx interrupts */
> -		pci_intx(pdev, 1);
> -	}
> +	ahci_init_irq(pdev, n_ports, hpriv);
> +
>  	hpriv->irq = pci_irq_vector(pdev, 0);
>  
>  	if (!(hpriv->cap & HOST_CAP_SSS) || ahci_ignore_sss)


-- 
Damien Le Moal
Western Digital Research

Re: [PATCH V2] simplify init function

[Niklas Cassel]

On Tue, Jan 14, 2025 at 10:03:44AM +0900, Damien Le Moal wrote:
> On 1/14/25 01:34, Tomas Henzl wrote:
> > by removing few lines. No functional change.
> 
> Looks OK to me, but:
> 
> The patch title should be: "ata: ahci: simplify init function"
> 
> And the commit message should also describe why it is OK to change
> ahci_init_irq() to be a void function. Can you send a V3 with that addressed
> please ?

I assume that this simplification is possible because sending in flags
(PCI_IRQ_MSIX | PCI_IRQ_INTX) to pci_alloc_irq_vectors() guarantees that
it will first try to allocate MSIX, if so, that should have be mentioned
in the commit message.



Also, you are just replacing pci_intx() with
pci_alloc_irq_vectors(.., PCI_IRQ_INTX), is this always safe?
If so, it should have been mentioned in the commit message.

pci_intx() is a hybrid function which can sometimes be managed through
devres. To remove this hybrid nature from pci_intx(), Philip has written
patches that ports users to either an always-managed or a never-managed
version.

A libata patch for this is currently queued via the PCI tree (pci/next),
see linux-next:
https://lore.kernel.org/linux-ide/Z1vFWyHkBD4d5xnG@ryzen/T/#mc20794f1e8712dafe77bc64c8da44c4d9b227b28
https://lore.kernel.org/linux-ide/Z1vFWyHkBD4d5xnG@ryzen/T/#m3a42ac564d97d10f8b1924c675efd144c845f8d5

Your patch conflicts with his series, which is already queued.


Kind regards,
Niklas


> 
> > 
> > Signed-off-by: Tomas Henzl <thenzl@redhat.com>
> > ---
> > V2: ahci_init_irq is now a void function
> > 
> >  drivers/ata/ahci.c | 23 ++++++++++++-----------
> >  1 file changed, 12 insertions(+), 11 deletions(-)
> > 
> > diff --git a/drivers/ata/ahci.c b/drivers/ata/ahci.c
> > index 8d27c567be1c..3ea2f3adf354 100644
> > --- a/drivers/ata/ahci.c
> > +++ b/drivers/ata/ahci.c
> > @@ -1665,13 +1665,15 @@ static int ahci_get_irq_vector(struct ata_host *host, int port)
> >  	return pci_irq_vector(to_pci_dev(host->dev), port);
> >  }
> >  
> > -static int ahci_init_msi(struct pci_dev *pdev, unsigned int n_ports,
> > +static void ahci_init_irq(struct pci_dev *pdev, unsigned int n_ports,
> >  			struct ahci_host_priv *hpriv)
> >  {
> >  	int nvec;
> >  
> > -	if (hpriv->flags & AHCI_HFLAG_NO_MSI)
> > -		return -ENODEV;
> > +	if (hpriv->flags & AHCI_HFLAG_NO_MSI) {
> > +		pci_alloc_irq_vectors(pdev, 1, 1, PCI_IRQ_INTX);
> > +		return;
> > +	}
> >  
> >  	/*
> >  	 * If number of MSIs is less than number of ports then Sharing Last
> > @@ -1685,7 +1687,7 @@ static int ahci_init_msi(struct pci_dev *pdev, unsigned int n_ports,
> >  			if (!(readl(hpriv->mmio + HOST_CTL) & HOST_MRSM)) {
> >  				hpriv->get_irq_vector = ahci_get_irq_vector;
> >  				hpriv->flags |= AHCI_HFLAG_MULTI_MSI;
> > -				return nvec;
> > +				return;
> >  			}
> >  
> >  			/*
> > @@ -1700,12 +1702,13 @@ static int ahci_init_msi(struct pci_dev *pdev, unsigned int n_ports,
> >  
> >  	/*
> >  	 * If the host is not capable of supporting per-port vectors, fall
> > -	 * back to single MSI before finally attempting single MSI-X.
> > +	 * back to single MSI before finally attempting single MSI-X or
> > +	 * a legacy INTx.
> >  	 */
> >  	nvec = pci_alloc_irq_vectors(pdev, 1, 1, PCI_IRQ_MSI);
> >  	if (nvec == 1)
> > -		return nvec;
> > -	return pci_alloc_irq_vectors(pdev, 1, 1, PCI_IRQ_MSIX);
> > +		return;
> > +	pci_alloc_irq_vectors(pdev, 1, 1, PCI_IRQ_MSIX | PCI_IRQ_INTX);
> >  }
> >  
> >  static void ahci_mark_external_port(struct ata_port *ap)
> > @@ -1985,10 +1988,8 @@ static int ahci_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
> >  	}
> >  	host->private_data = hpriv;
> >  
> > -	if (ahci_init_msi(pdev, n_ports, hpriv) < 0) {
> > -		/* legacy intx interrupts */
> > -		pci_intx(pdev, 1);
> > -	}
> > +	ahci_init_irq(pdev, n_ports, hpriv);
> > +
> >  	hpriv->irq = pci_irq_vector(pdev, 0);
> >  
> >  	if (!(hpriv->cap & HOST_CAP_SSS) || ahci_ignore_sss)
> 
> 
> -- 
> Damien Le Moal
> Western Digital Research

Re: [PATCH V2] simplify init function

[Tomas Henzl]

On 1/14/25 2:03 AM, Damien Le Moal wrote:
> On 1/14/25 01:34, Tomas Henzl wrote:
>> by removing few lines. No functional change.
> 
> Looks OK to me, but:
> 
> The patch title should be: "ata: ahci: simplify init function"
> 
> And the commit message should also describe why it is OK to change
> ahci_init_irq() to be a void function. Can you send a V3 with that addressed
> please ?
sure
> 
>>
>> Signed-off-by: Tomas Henzl <thenzl@redhat.com>
>> ---
>> V2: ahci_init_irq is now a void function
>>
>>  drivers/ata/ahci.c | 23 ++++++++++++-----------
>>  1 file changed, 12 insertions(+), 11 deletions(-)
>>
>> diff --git a/drivers/ata/ahci.c b/drivers/ata/ahci.c
>> index 8d27c567be1c..3ea2f3adf354 100644
>> --- a/drivers/ata/ahci.c
>> +++ b/drivers/ata/ahci.c
>> @@ -1665,13 +1665,15 @@ static int ahci_get_irq_vector(struct ata_host *host, int port)
>>  	return pci_irq_vector(to_pci_dev(host->dev), port);
>>  }
>>  
>> -static int ahci_init_msi(struct pci_dev *pdev, unsigned int n_ports,
>> +static void ahci_init_irq(struct pci_dev *pdev, unsigned int n_ports,
>>  			struct ahci_host_priv *hpriv)
>>  {
>>  	int nvec;
>>  
>> -	if (hpriv->flags & AHCI_HFLAG_NO_MSI)
>> -		return -ENODEV;
>> +	if (hpriv->flags & AHCI_HFLAG_NO_MSI) {
>> +		pci_alloc_irq_vectors(pdev, 1, 1, PCI_IRQ_INTX);
>> +		return;
>> +	}
>>  
>>  	/*
>>  	 * If number of MSIs is less than number of ports then Sharing Last
>> @@ -1685,7 +1687,7 @@ static int ahci_init_msi(struct pci_dev *pdev, unsigned int n_ports,
>>  			if (!(readl(hpriv->mmio + HOST_CTL) & HOST_MRSM)) {
>>  				hpriv->get_irq_vector = ahci_get_irq_vector;
>>  				hpriv->flags |= AHCI_HFLAG_MULTI_MSI;
>> -				return nvec;
>> +				return;
>>  			}
>>  
>>  			/*
>> @@ -1700,12 +1702,13 @@ static int ahci_init_msi(struct pci_dev *pdev, unsigned int n_ports,
>>  
>>  	/*
>>  	 * If the host is not capable of supporting per-port vectors, fall
>> -	 * back to single MSI before finally attempting single MSI-X.
>> +	 * back to single MSI before finally attempting single MSI-X or
>> +	 * a legacy INTx.
>>  	 */
>>  	nvec = pci_alloc_irq_vectors(pdev, 1, 1, PCI_IRQ_MSI);
>>  	if (nvec == 1)
>> -		return nvec;
>> -	return pci_alloc_irq_vectors(pdev, 1, 1, PCI_IRQ_MSIX);
>> +		return;
>> +	pci_alloc_irq_vectors(pdev, 1, 1, PCI_IRQ_MSIX | PCI_IRQ_INTX);
>>  }
>>  
>>  static void ahci_mark_external_port(struct ata_port *ap)
>> @@ -1985,10 +1988,8 @@ static int ahci_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
>>  	}
>>  	host->private_data = hpriv;
>>  
>> -	if (ahci_init_msi(pdev, n_ports, hpriv) < 0) {
>> -		/* legacy intx interrupts */
>> -		pci_intx(pdev, 1);
>> -	}
>> +	ahci_init_irq(pdev, n_ports, hpriv);
>> +
>>  	hpriv->irq = pci_irq_vector(pdev, 0);
>>  
>>  	if (!(hpriv->cap & HOST_CAP_SSS) || ahci_ignore_sss)
> 
>