Re: [PATCH net-next 5/9] bnxt_en: Remove BNXT_FLAG_USING_MSIX flag

On Mon, Jul 15, 2024 at 10:32 AM Bjorn Helgaas [off-list ref] wrote:

On Sat, Jul 13, 2024 at 04:43:35PM -0700, Michael Chan wrote:

quoted

Now that we only support MSIX, the BNXT_FLAG_USING_MSIX is always true.
Remove it and any if conditions checking for it.  Remove the INTX
handler and associated logic.

The cover letter says new firmware (the revision isn't mentioned)
doesn't support INTx.  I guess it's OK if the new driver without INTx
support runs on adapters with old firmware that still supports INTx?
So the INTx support was never a real benefit?  I assume this driver
change won't force a simultaneous firmware update?  The old driver
might work in a "pci=nomsi" situation, but the new one probably won't?
Just checking to be sure these are all acceptable consequences.

INTx was used as a fall-back mechanism in case MSIX wasn't available.

A new driver running on a NIC with older FW will work fine in MSIX
mode.  MSIX is always supported on any version of FW.  A new driver
obviously will not work in INTx mode even if the FW supports it.  But
INTx hasn't been tested for so many years that I won't be surprised if
it doesn't work using all older components that should support it.
Thanks.