Thread (8 messages) 8 messages, 3 authors, 2015-06-04

[PATCH v4 3/3] AHCI: Add generic MSI-X interrupt support to SATA PCI driver

From: tj@kernel.org (Tejun Heo)
Date: 2015-06-03 05:44:42
Also in: linux-ide, lkml

Hello, Robert.

Maybe qualifying the subject that it's only for single IRQ would be a
good idea?
quoted hunk ↗ jump to hunk
@@ -52,6 +53,7 @@
 
 enum {
 	AHCI_PCI_BAR_STA2X11	= 0,
+	AHCI_PCI_BAR_CAVIUM	= 0,
 	AHCI_PCI_BAR_ENMOTUS	= 2,
 	AHCI_PCI_BAR_STANDARD	= 5,
I thought I already asked but please separate out CAVIUM specific
changes from msix implementation and follow up with why cavium depends
on msix support.
+static int ahci_init_msix(struct pci_dev *pdev, unsigned int n_ports,
+			  struct ahci_host_priv *hpriv)
+{
Please add a comment describing that it's for single msix only and why
that'd be necessary for certain controllers.

...
+	/*
+	 * Per-port msix interrupts are not supported. Assume single
+	 * port interrupts for:
+	 *
+	 *  n_ports == 1, or
+	 *  nvec < n_ports.
+	 *
+	 * We also need to check for n_ports != 0 which is implicitly
+	 * covered here since nvec > 0.
+	 */
+	if (n_ports != 1 && nvec >= n_ports) {
+		rc = -ENOSYS;
+		goto fail;
+	}
Didn't I ask this one too the last time?  Can you explain why we can't
initialize single IRQ mode if nvec >= n_ports?
quoted hunk ↗ jump to hunk
@@ -1260,6 +1339,10 @@ static int ahci_init_interrupts(struct pci_dev *pdev, unsigned int n_ports,
 	if (nvec >= 0)
 		return nvec;
 
+	nvec = ahci_init_msix(pdev, n_ports, hpriv);
+	if (nvec >= 0)
+		return nvec;
Please add a comment explaining why we're doing msix after msi.

Thanks.

-- 
tejun
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