On 9/7/20 9:23 AM, Klaus Jensen wrote:
> On Sep 7 04:28, Philippe Mathieu-Daudé wrote:
>> +David in case
>>
>> On 9/4/20 4:19 PM, Klaus Jensen wrote:
>>> From: Klaus Jensen <k.jen...@samsung.com>
>>>
>>> There are two reasons for changing this:
>>>
>>> 1. The nvme device currently uses an internal Intel device id.
>>>
>>> 2. Since commits "nvme: fix write zeroes offset and count" and "nvme:
>>> support multiple namespaces" the controller device no longer has
>>> the quirks that the Linux kernel think it has.
>>>
>>> As the quirks are applied based on pci vendor and device id, change
>>> them to get rid of the quirks.
>>>
>>> To keep backward compatibility, add a new 'x-use-intel-id' parameter to
>>> the nvme device to force use of the Intel vendor and device id. This is
>>> off by default but add a compat property to set this for 5.1 machines
>>> and older.
>>
>> So now what happens if you start a 5.1 machine with a recent kernel?
>> Simply the kernel will use unnecessary quirks, or are there more
>> changes in behavior?
>>
>
> Yes, the kernel will then just apply unneccesary quirks, these are:
>
> 1. NVME_QUIRK_IDENTIFY_CNS which says that the device does not support
> anything else than values 0x0 and 0x1 for CNS (Identify Namespace and
> Identify Namespace). With multiple namespace support, this just
> means that the kernel will "scan" namespaces instead of using
> "Active Namespace ID list" (CNS 0x2).
>
> 2. NVME_QUIRK_DISABLE_WRITE_ZEROES. The nvme device started out with a
> broken Write Zeroes implementation which has since been fixed in
> commit 9d6459d21a6e ("nvme: fix write zeroes offset and count").
OK thanks. Can you amend that information in the commit
description please?
Thanks,
Phil.
