ASoC: SOF: Intel: hda: fix MSI handling

The addition of a kernel module parameter to optionally disable MSI
had the side effect of permanently disabling it.

The return value of pci_alloc_irq_vectors() is the number of allocated
vectors or a negative number on error, so testing with the ! operator
is not quite right. It was one optimization too far.

Restore previous behavior to use MSI by default, unless the user
selects not to do so or the allocation of irq_vectors fails.

Fixes: 672ff5e3596ee ('ASoC: SOF: Intel: hda: add a parameter to disable MSI')
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Link: https://lore.kernel.org/r/20190806170603.10815-1-pierre-louis.bossart@linux.intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>

diff --git a/sound/soc/sof/intel/hda.c b/sound/soc/sof/intel/hda.c
index 79cce20666b6cd792c3225743a9d116b37457ffd..53813de7844e05dc67b070edb7aecd674be98b71 100644 (file)
--- a/sound/soc/sof/intel/hda.c
+++ b/sound/soc/sof/intel/hda.c
@@ -537,7 +537,7 @@ int hda_dsp_probe(struct snd_sof_dev *sdev)
         * if it fails, use legacy interrupt mode
         * TODO: support msi multiple vectors
         */
-       if (hda_use_msi && !pci_alloc_irq_vectors(pci, 1, 1, PCI_IRQ_MSI)) {
+       if (hda_use_msi && pci_alloc_irq_vectors(pci, 1, 1, PCI_IRQ_MSI) > 0) {
                dev_info(sdev->dev, "use msi interrupt mode\n");
                hdev->irq = pci_irq_vector(pci, 0);
                /* ipc irq number is the same of hda irq */