[PATCH v2 3/3] PCI/MSI: Add TODO comment about legacy pcim_enable_device() side-effect

[Shawn Lin <shawn.lin@rock-chips.com>]

Add a TODO comment in pci/msi/msi.c to document that the automatic IRQ
vector management activated by pcim_enable_device() is a dangerous and
confusing.

The comment is placed near pcim_setup_msi_release() where the automatic
management is implemented, serving as a marker for future cleanup work.

Suggested-by: Philipp Stanner <phasta@kernel.org>
Signed-off-by: Shawn Lin <shawn.lin@rock-chips.com>

---

Changes in v2: None

 drivers/pci/msi/msi.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/drivers/pci/msi/msi.c b/drivers/pci/msi/msi.c
index e241217..81d24a2 100644
--- a/drivers/pci/msi/msi.c
+++ b/drivers/pci/msi/msi.c
@@ -77,6 +77,16 @@ static void pcim_msi_release(void *pcidev)
 /*
  * Needs to be separate from pcim_release to prevent an ordering problem
  * vs. msi_device_data_release() in the MSI core code.
+ *
+ * TODO: Remove the legacy side-effect of pcim_enable_device() that
+ * activates automatic IRQ vector management. This design is dangerous
+ * and confusing because it switches normally un-managed functions
+ * into managed mode. Drivers should explicitly manage their IRQ vectors
+ * without this implicit behavior.
+ *
+ * The current implementation uses both pdev->is_managed and
+ * pdev->is_msi_managed flags, which adds unnecessary complexity.
+ * This should be simplified in a future kernel version.
  */
 static int pcim_setup_msi_release(struct pci_dev *dev)
 {
-- 
2.7.4