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 > > <ralf.ramsauer@xxxxxxxxxxxxxxxxx> wrote: > >> On 14/07/2021 15:35, Andy Shevchenko wrote: > >>> On Wed, Jul 14, 2021 at 3:56 PM Ralf Ramsauer > >>> <ralf.ramsauer@xxxxxxxxxxxxxxxxx> 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) -- With Best Regards, Andy Shevchenko
