Re: [patch v2] tg3: Disable tg3 PCIe AER on system reboot

[Przemek Kitszel <przemyslaw.kitszel@intel.com>]

On 11/29/24 21:36, Lenny Szubowicz wrote:
> Disable PCIe AER on the tg3 device on system reboot on a limited
> list of Dell PowerEdge systems. This prevents a fatal PCIe AER event
> on the tg3 device during the ACPI _PTS (prepare to sleep) method for
> S5 on those systems. The _PTS is invoked by acpi_enter_sleep_state_prep()
> as part of the kernel's reboot sequence as a result of commit
> 38f34dba806a ("PM: ACPI: reboot: Reinstate S5 for reboot").
> 
> There was an earlier fix for this problem by commit 2ca1c94ce0b6
> ("tg3: Disable tg3 device on system reboot to avoid triggering AER").
> But it was discovered that this earlier fix caused a reboot hang
> when some Dell PowerEdge servers were booted via ipxe. To address
> this reboot hang, the earlier fix was essentially reverted by commit
> 9fc3bc764334 ("tg3: power down device only on SYSTEM_POWER_OFF").
> This re-exposed the tg3 PCIe AER on reboot problem.
> 
> This fix is not an ideal solution because the root cause of the AER
> is in system firmware. Instead, it's a targeted work-around in the
> tg3 driver.
> 
> Note also that the PCIe AER must be disabled on the tg3 device even
> if the system is configured to use "firmware first" error handling.
> 
> Fixes: 9fc3bc764334 ("tg3: power down device only on SYSTEM_POWER_OFF")
> Signed-off-by: Lenny Szubowicz <lszubowi@redhat.com>

the bug occurs also on Intel drivers, we even got the ~very same fix
proposed:
https://lore.kernel.org/netdev/20241227035459.90602-1-yue.zhao@shopee.com/T/

I believe that such fix should be centralized, instead of repeating for
each driver. Especially that the list of platforms is likely to be
extended in the future.

It's sad that we don't have Dell cced here, I'm trying to get some
relevant contacts, but without success so far.