There is no functional change done with this patch.
This patch moves all the IRQ vector allocations into a single
function. Instead of having the allocations spread out over
two separate call sites everything will be handled in ahci_init_irq.
Also a direct call into pci(m)_intx will be removed.
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.
The two last steps can be merged into a single one which are
the msi-x and legacy irq option.
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.
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)
V4: done changes in patch body asked for by Niklas, like removing
double newlines and few others
---
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 52ae8f9a7dd6..76d3654a879c 100644
--- a/drivers/ata/ahci.c
+++ b/drivers/ata/ahci.c
@@ -1667,13 +1667,15 @@ 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
@@ -1687,7 +1689,7 @@ 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;
}
/*
@@ -1702,12 +1704,13 @@ 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)
@@ -1987,10 +1990,8 @@ 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)
--
2.48.1
