On 16/07/2021 19:27, Andy Shevchenko wrote: > On Fri, Jul 16, 2021 at 05:27:36PM +0200, Ralf Ramsauer wrote: >> On 16/07/2021 17:01, Andy Shevchenko wrote: >>> On Fri, Jul 16, 2021 at 4:07 PM Ralf Ramsauer >>> wrote: >>>> On 14/07/2021 15:35, Andy Shevchenko wrote: >>>>> On Wed, Jul 14, 2021 at 3:56 PM Ralf Ramsauer >>>>> wrote: >>>>>> On 14/07/2021 08:54, Jiri Slaby wrote: >>>>>>> On 13. 07. 21, 12:40, Andy Shevchenko wrote: >>>>> >>>>>>> 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? >>> >>>> So I found a no-name el-cheapo card that has some issues with MSI: >>> >>> Win Chip Head (WCH) >>> >>>> 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