Hi Damien,
the V3 patch applies to the for-6.15 branch with just an offset.
Can you take it as it is or do you want me to resend?
Regards,
Tomas
On 1/15/25 4:08 PM, Tomas Henzl wrote:
> On 1/15/25 3:30 AM, Damien Le Moal wrote:
>> On 1/15/25 03:29, Tomas Henzl wrote:
>>> by removing few lines. No functional change.
>>>
>>> The main part of this change is done by adding a PCI_IRQ_INTX flag into
>>> an already existing pci_alloc_irq_vectors invocation.
>>> In the current implementation of the pci_alloc_irq_vectors is the sequence of calls
>>> msi-x -> msi -> legacy irq and whatever there succeeds stops the
>>> call chain. That makes it impossible to merge all instances into as a single call
>>> to pci_alloc_irq_vectors since the order of calls there is:
>>> multiple msi-x
>>> a single msi
>>> a single msi-x
>>> a legacy irq.
>>> but the two last steps can be merged into one which are the msi-x and legacy
>>> irq option. With this change we remove a pci(m)_intx call.
>>> When PCI_IRQ_INTX flag is set the pci_alloc_irq_vectors succeeds in almost
>>> all cases - that makes it possible to convert ahci_init_irq(msi) into a void function.
>>> The exception is when dev->irq is zero then the pci_alloc_irq_vectors
>>> may return with an error code also pci_intx isn't called from pci_alloc_irq_vectors
>>> and thus certain pci calls aren't performed.
>>> That's just a negligible issue as later in ahci_init_one the (zero)
>>> value of dev->irq is via pci_irq_vector assigned to hpriv->irq.
>>> That value is then later tested in ahci_host_activate->ata_host_activate where
>>> it is welcomed with a WARN_ON message and fails with setting up irq and
>>> then the probe function (ahci_init_one) fails. The special zero value's
>>> meaning is that polling mode is being be set up which isn't the case.
>>>
>>
>> Extra blank line not need here.
>>
>> Beside that, looks OK now. But as Niklas pointed out, this conflicts with a
>> patch in the PCI tree. And given that it is too late to queue that for 6.14, can
>> you resend a rebased version once 6.14-rc1 is out in a couple of weeks ?
>
> I can do that, thanks.
>
>>
>> Thanks !
>>
>>>
>>> Signed-off-by: Tomas Henzl <thenzl@xxxxxxxxxx>
>>> ---
>>> V2: ahci_init_irq is now a void function
>>> V3: a) added an explanation of why we may convert ahci_init_irq into
>>> a void function
>>> b) fixed the subject line
>>> c) added an explanation of why calling pci_alloc_irq_vectors instead
>>> of pci_intx is safe
>>> d) rebased to latest code state (pci_intx->pcim_intx)
>>>
>>> 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 */
>>> - pcim_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)
>>
>>
>
