Messages in this thread | | | Date | Mon, 27 Feb 2023 14:23:56 -0600 | Subject | Re: [RFC 0/6] pcmcia: separate 16-bit support from cardbus | From | Larry Finger <> |
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On 2/27/23 07:34, Arnd Bergmann wrote: > From: Arnd Bergmann <arnd@arndb.de> > > Based on some recent discussions [1][2][3], I experimented wtih what > drivers/pcmcia would look like if we completely removed 16-bit support, > which was one of the options that Dominik suggested for winding down > pcmcia maintenance. > > The remaining cardbus/yenta support is essentially a PCI hotplug driver > with a slightly unusual sysfs interface, and it would still support all > 32-bit cardbus hosts and cards, but no longer work with the even older > 16-bit cards that require the pcmcia_driver infrastructure. > > I don't expect this to be a problem normal laptop support, as the last > PC models that predate Cardbus support (e.g. 1997 ThinkPad 380ED) are > all limited to i586MMX CPUs and 80MB of RAM. This is barely enough to > boot Tiny Core Linux but not a regular distro. > > Support for device drivers is somewhat less clear. Losing support for > 16-bit cards in cardbus sockets is obviously a limiting factor for > anyone who still has those cards, but there is also a good chance that > the only reason to keep the cards around is for using them in pre-cardbus > machines that cannot be upgrade to 32-bit devices. > > Completely removing the 16-bit PCMCIA support would however break some > 20+ year old embedded machines that rely on CompactFlash cards as their > mass-storage device (extension), this notably includes early PocketPC > models and the reference implementations for OMAP1, StrongARM1100, > Alchemy and PA-Semi. All of these are still maintained, though most > of the PocketPC machines got removed in the 6.3 merge window and the > PA-Semi Electra board is the only one that was introduced after > 2003. > > The approach that I take in this series is to split drivers/pcmcia > into two mutually incompatible parts: the Cardbus support contains > all the code that is relevant for post-1997 laptops and gets moved > to drivers/pci/hotplug, while the drivers/pcmcia/ subsystem is > retained for both the older laptops and the embedded systems but no > longer works with the yenta socket host driver. The BCM63xx > PCMCIA/Cardbus host driver appears to be unused and conflicts with > this series, so it is removed in the process. > > My series does not touch any of the pcmcia_driver instances, but > if there is consensus about splitting out the cardbus support, > a lot of them can probably get removed as a follow-up.
Arnd,
Your patch set also breaks my PowerBook G4. The output of 'lspci -nn | grep Network' shows the following before your patch is applied:
0001:10:12.0 Network controller [0280]: Broadcom Inc. and subsidiaries BCM4306 802.11b/g Wireless LAN Controller [14e4:4320] (rev 03) 0001:11:00.0 Network controller [0280]: Broadcom Inc. and subsidiaries BCM4318 [AirForce One 54g] 802.11g Wireless LAN Controller [14e4:4318] (rev 02)
The first of these is broken and built into the laptop. The second is plugged into a PCMCIA slot, and uses yenta-socket as a driver.
When your patches are applied, the second entry vanishes.
Yes, this hardware is ancient, but I would prefer having this wifi interface work. I can provide any output you need.
Larry
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