@@ -1091,6 +1091,14 @@ static inline void ahci_gtf_filter_workaround(struct ata_host *host)
{}
#endif
+static int ahci_get_mrsm(struct ahci_host_priv *hpriv)
+{
+ void __iomem *mmio = hpriv->mmio;
+ u32 ctl = readl(mmio + HOST_CTL);
+
+ return ctl & HOST_MRSM;
+}
+
int ahci_init_interrupts(struct pci_dev *pdev, unsigned int n_ports,
struct ahci_host_priv *hpriv)
{
@@ -1116,6 +1124,15 @@ int ahci_init_interrupts(struct pci_dev *pdev, unsigned int n_ports,
if (rc)
goto intx;
+ /*
+ * Fallback to single MSI mode if the controller enforced MRSM mode
+ */
+ if (ahci_get_mrsm(hpriv)) {
+ pci_disable_msi(pdev);
+ printk(KERN_INFO "ahci: MRSM is on, fallback to single MSI\n");
+ goto single_msi;
+ }
+
return nvec;
single_msi:
@@ -91,6 +91,7 @@ enum {
/* HOST_CTL bits */
HOST_RESET = (1 << 0), /* reset controller; self-clear */
HOST_IRQ_EN = (1 << 1), /* global IRQ enable */
+ HOST_MRSM = (1 << 2), /* MSI Revert to Single Message */
HOST_AHCI_EN = (1 << 31), /* AHCI enabled */
/* HOST_CAP bits */
Do not trust the hardware and always check if MSI Revert to Single Message mode was enforced. Fall back to the single MSI mode in case it did. Not doing so might screw up the interrupt handling. Signed-off-by: Alexander Gordeev <agordeev@redhat.com> --- drivers/ata/ahci.c | 17 +++++++++++++++++ drivers/ata/ahci.h | 1 + 2 files changed, 18 insertions(+), 0 deletions(-)