On 23 March 2018 at 15:09, Juri Lelli <juri.lelli@xxxxxxxxx> wrote: > On 23/03/18 14:43, Rafał Miłecki wrote: >> Hi, >> >> On 23 March 2018 at 10:47, Juri Lelli <juri.lelli@xxxxxxxxx> wrote: >> > I've got a Dell XPS 13 9343/0TM99H (BIOS A15 01/23/2018) mounting a >> > BCM4352 802.11ac (rev 03) wireless card and so far I've been using it on >> > Fedora with broadcom-wl package (which I believe installs Broadcom's STA >> > driver?). It works good apart from occasional hiccups after suspend. >> > >> > I'd like to get rid of that dependency (you can understand that it's >> > particularly annoying when testing mainline kernels), but I found out >> > that support for my card is BROKEN in mainline [1]. Just to see what >> > happens, I forcibly enabled it witnessing that it indeed crashes like >> > below as Kconfig warns. :) >> > >> > bcma: bus0: Found chip with id 0x4352, rev 0x03 and package 0x00 >> > bcma: bus0: Core 0 found: ChipCommon (manuf 0x4BF, id 0x800, rev 0x2B, class 0x0) >> > bcma: bus0: Core 1 found: IEEE 802.11 (manuf 0x4BF, id 0x812, rev 0x2A, class 0x0) >> > bcma: bus0: Core 2 found: ARM CR4 (manuf 0x4BF, id 0x83E, rev 0x02, class 0x0) >> > bcma: bus0: Core 3 found: PCIe Gen2 (manuf 0x4BF, id 0x83C, rev 0x01, class 0x0) >> > bcma: bus0: Core 4 found: USB 2.0 Device (manuf 0x4BF, id 0x81A, rev 0x11, class 0x0) >> > bcma: Unsupported SPROM revision: 11 >> > bcma: bus0: Invalid SPROM read from the PCIe card, trying to use fallback SPROM >> > bcma: bus0: Using fallback SPROM failed (err -2) >> > bcma: bus0: No SPROM available >> > bcma: bus0: Bus registered >> > b43-phy0: Broadcom 4352 WLAN found (core revision 42) >> > b43-phy0: Found PHY: Analog 12, Type 11 (AC), Revision 1 >> > b43-phy0: Found Radio: Manuf 0x17F, ID 0x2069, Revision 4, Version 0 >> > BUG: unable to handle kernel NULL pointer dereference at 0000000000000000 >> >> This isn't really useful without a full backtrace. > > Sure. I cut it here because I didn't expect people to debug what is > already known to be broken (but still it seemed to carry useful > information about the hw). :) Please paste the remaining part if you still got it. >> > So, question: is replacing my card the only way I can get rid of this >> > downstream dependency? :( >> >> It's definitely the cheapest way. Getting AC PHY into anything usable >> (proper setup that will allow Tx & Rx anything) would probably take >> weeks or months of development. I'm not even going to estimate cost of >> adding support for 802.11n and 802.11ac features. I was the last >> person actively working on b43, right now I spend my free time on >> other hobby projects. Few people were planning to help but it seems it >> never worked out for them. > > I see. Just wondering why even if Broadcom's STA solution seems to work > fine, it is not mainline. Maybe a maintenance problem? But Fedora ships > with very recent kernels, so I'd expect the driver to work with mainline > (I tried compiling that against mainline, but I got errors that I didn't > spend time figuring out how to fix). > > Do you know what's the deal w.r.t. the STA driver? Driver being closed source and company not willing to open source it is usually a big problem getting it mainline... -- Rafał
