Re: [PATCH v2 3/5] bus: mhi: host: pci_generic: Remove MHI driver and ensure graceful device recovery

From: Konrad Dybcio
Date: Wed Jul 23 2025 - 08:51:22 EST


On 7/23/25 2:11 PM, Vivek Pernamitta wrote:
>
>
> On 7/10/2025 6:12 PM, Konrad Dybcio wrote:
>> On 7/10/25 10:58 AM, Vivek.Pernamitta@xxxxxxxxxxx wrote:
>>> From: Vivek Pernamitta <quic_vpernami@xxxxxxxxxxx>
>>>
>>> When the MHI driver is removed from the host side, it is crucial to ensure
>>> graceful recovery of the device. To achieve this, the host driver will
>>> perform the following steps:
>>>
>>> 1. Disable SRIOV for any SRIOV-enabled devices on the Physical Function.
>>> 2. Perform a SOC_RESET on Physical Function (PF).
>>>
>>> Disabling SRIOV ensures that all virtual functions are properly shut down,
>>> preventing any potential issues during the reset process. Performing
>>> SOC_RESET on each physical function guarantees that the device is fully
>>> reset and ready for subsequent operations.
>>>
>>> Signed-off-by: Vivek Pernamitta <quic_vpernami@xxxxxxxxxxx>
>>> ---

[...]

>> It seems rather unlikely that out off all MHI devices, only QDU100
>> needs this quirk when working under SR-IOV
> The reset_on_driver_unbind flag has been explicitly added for the QDU100
> device. While other devices might enter RAMDUMP mode and wait when a SOC
> reset is issued, the QDU100 device will pass through without entering
> RAMDUMP mode

Rather inconveniently, this is not something that you mentioned in
the commit message.. Especially in the middle of a series that focuses
on enabling SR-IOV which suggests it's strictly related to virtualization,
making it difficult or impossible to understand the problem that this
patch is actually solving.

Please rewrite the commit message.

Konrad