On 16/07/2021 19:27, Andy Shevchenko wrote:

On Fri, Jul 16, 2021 at 05:27:36PM +0200, Ralf Ramsauer wrote:

quoted

On 16/07/2021 17:01, Andy Shevchenko wrote:

quoted

On Fri, Jul 16, 2021 at 4:07 PM Ralf Ramsauer
[off-list ref] wrote:

quoted

On 14/07/2021 15:35, Andy Shevchenko wrote:

quoted

On Wed, Jul 14, 2021 at 3:56 PM Ralf Ramsauer
[off-list ref] wrote:

quoted

On 14/07/2021 08:54, Jiri Slaby wrote:

quoted

On 13. 07. 21, 12:40, Andy Shevchenko wrote:

quoted

quoted

Hmm, have you checked the commit which introduced the whitelist?

    Nevertheless, this needs to handled with care: while many 8250 devices
    actually claim to support MSI(-X) interrupts it should not be
enabled be
    default. I had at least one device in my hands with broken MSI
    implementation.

    So better introduce a whitelist with devices that are known to support
    MSI(-X) interrupts. I tested all devices mentioned in the patch.


You should have at least CCed the author for an input.

Yep, back then I was testing three different 8250 pci cards. All of them
claimed to support MSI, while one really worked with MSI, the one that I
whitelisted. So I thought it would be better to use legacy IRQs as long
as no one tested a specific card to work with MSI.

Can you shed a light eventually what those cards are?

quoted

So I found a no-name el-cheapo card that has some issues with MSI:

Win Chip Head (WCH)

quoted

18:00.0 Serial controller: Device 1c00:3253 (rev 10) (prog-if 05 [16850])

Thank you!

One more thing, ist it possible to see entire PCI configuration space (w/ or
w/o MSI, I don't think it matters)? Something like

	`lspci -nk -vvv -xxx -s 18:0`

to run.

(I believe there are a lot of 0xff bytes)

Find it attached, w/ MSI+. Not that many, only the 0xffs for the MSI
mask, afaict.

  Ralf