More than 1/3 of the n_gsm code has been contributed by us in the last
1.5 years, completing conformance with the standard and stabilizing the
driver:
- added UI (unnumbered information) frame support
- added PN (parameter negotiation) message handling and function support
- added optional keep-alive control link supervision via test messages
- added TIOCM_OUT1 and TIOCM_OUT2 to allow responder to operate as modem
- added TIOCMIWAIT support on virtual ttys
- added additional ioctls and parameters to configure the new functions
- added overall locking mechanism to avoid data race conditions
- added outgoing data flow to decouple physical from virtual tty handling
for better performance and to avoid dead-locks
- fixed advanced option mode implementation
- fixed convergence layer type 2 implementation
- fixed handling of CLD (multiplexer close down) messages
- fixed broken muxer close down procedure
- and many more bug fixes
With this most of our initial RFC has been implemented. It gives the driver
a quality boost unseen in the decade before.
Add a copyright notice to the n_gsm files to highlight this contribution.
Link: https://lore.kernel.org/all/20220225080758.2869-1-daniel.starke@siemens.com/
Signed-off-by: Daniel Starke <daniel.starke@siemens.com>
Link: https://lore.kernel.org/r/20231027053903.1886-1-daniel.starke@siemens.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
gsm_cleanup_mux() cleans up the gsm by closing all DLCIs, stopping all
timers, removing the virtual tty devices and clearing the data queues.
This procedure, however, may cause subsequent changes of the virtual modem
status lines of a DLCI. More data is being added the outgoing data queue
and the deleted kick timer is restarted to handle this. At this point many
resources have already been removed by the cleanup procedure. Thus, a
kernel panic occurs.
Fix this by proving in gsm_modem_update() that the cleanup procedure has
not been started and the mux is still alive.
Note that writing to a virtual tty is already protected by checks against
the DLCI specific connection state.
Fixes: c568f7086c ("tty: n_gsm: fix missing timer to handle stalled links")
Cc: stable <stable@kernel.org>
Signed-off-by: Daniel Starke <daniel.starke@siemens.com>
Link: https://lore.kernel.org/r/20231026055844.3127-1-daniel.starke@siemens.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Some of the later revisions of the Brainboxes PX cards are based
on the Oxford Semiconductor chipset. Due to the chip's unique setup
these cards need to be initialised.
Previously these were tested against a reference card with the same broken
baudrate on another PC, cancelling out the effect. With this patch they
work and can transfer/receive find against an FTDI-based device.
Add all of the cards which require this setup to the quirks table.
Thanks to Maciej W. Rozycki for clarification on this chip.
Fixes: ef5a03a26c ("tty: 8250: Add support for Brainboxes PX cards.")
Cc: stable@vger.kernel.org
Signed-off-by: Cameron Williams <cang1@live.co.uk>
Link: https://lore.kernel.org/r/DU0PR02MB7899D222A4AB2A4E8C57108FC4DBA@DU0PR02MB7899.eurprd02.prod.outlook.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
On unplug of a Xen console, xencons_disconnect_backend() unconditionally
calls free_irq() via unbind_from_irqhandler(), causing a warning of
freeing an already-free IRQ:
(qemu) device_del con1
[ 32.050919] ------------[ cut here ]------------
[ 32.050942] Trying to free already-free IRQ 33
[ 32.050990] WARNING: CPU: 0 PID: 51 at kernel/irq/manage.c:1895 __free_irq+0x1d4/0x330
It should be using evtchn_put() to tear down the event channel binding,
and let the Linux IRQ side of it be handled by notifier_del_irq() through
the HVC code.
On which topic... xencons_disconnect_backend() should call hvc_remove()
*first*, rather than tearing down the event channel and grant mapping
while they are in use. And then the IRQ is guaranteed to be freed by
the time it's torn down by evtchn_put().
Since evtchn_put() also closes the actual event channel, avoid calling
xenbus_free_evtchn() except in the failure path where the IRQ was not
successfully set up.
However, calling hvc_remove() at the start of xencons_disconnect_backend()
still isn't early enough. An unplug request is indicated by the backend
setting its state to XenbusStateClosing, which triggers a notification
to xencons_backend_changed(), which... does nothing except set its own
frontend state directly to XenbusStateClosed without *actually* tearing
down the HVC device or, you know, making sure it isn't actively in use.
So the backend sees the guest frontend set its state to XenbusStateClosed
and stops servicing the interrupt... and the guest spins for ever in the
domU_write_console() function waiting for the ring to drain.
Fix that one by calling hvc_remove() from xencons_backend_changed() before
signalling to the backend that it's OK to proceed with the removal.
Tested with 'dd if=/dev/zero of=/dev/hvc1' while telling Qemu to remove
the console device.
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20231020161529.355083-4-dwmw2@infradead.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The xencons_connect_backend() function allocates a local interdomain
event channel with xenbus_alloc_evtchn(), then calls
bind_interdomain_evtchn_to_irq_lateeoi() to bind to that port# on the
*remote* domain.
That doesn't work very well:
(qemu) device_add xen-console,id=con1,chardev=pty0
[ 44.323872] xenconsole console-1: 2 xenbus_dev_probe on device/console/1
[ 44.323995] xenconsole: probe of console-1 failed with error -2
Fix it to use bind_evtchn_to_irq_lateeoi(), which does the right thing
by just binding that *local* event channel to an irq. The backend will
do the interdomain binding.
This didn't affect the primary console because the setup for that is
special — the toolstack allocates the guest event channel and the guest
discovers it with HVMOP_get_param.
Fixes: fe415186b4 ("xen/console: harden hvc_xen against event channel storms")
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Reviewed-by: Juergen Gross <jgross@suse.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20231020161529.355083-2-dwmw2@infradead.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Separating the VGA console screen_info from the EFI one unfortunately
caused a build failure for footbridge that I had never caught
with randconfig builds:
arch/arm/kernel/setup.c:932:27: error: static declaration of 'vgacon_screen_info' follows non-static declaration
932 | static struct screen_info vgacon_screen_info = {
| ^~~~~~~~~~~~~~~~~~
In file included from arch/arm/kernel/setup.c:44:
arch/arm/include/asm/setup.h:40:27: note: previous declaration of 'vgacon_screen_info' with type 'struct screen_info'
40 | extern struct screen_info vgacon_screen_info;
| ^~~~~~~~~~~~~~~~~~
arm-linux-gnueabi-ld: drivers/video/console/dummycon.o: in function `dummycon_init':
dummycon.c:(.text+0xe4): undefined reference to `screen_info'
Make sure the variable is global to avoid the conflict with the extern
declaration, and make it work in dummycon.c
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Link: https://lore.kernel.org/r/20231017093947.3627976-2-arnd@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
After the vga console no longer relies on global screen_info, there are
only two remaining use cases:
- on the x86 architecture, it is used for multiple boot methods
(bzImage, EFI, Xen, kexec) to commucate the initial VGA or framebuffer
settings to a number of device drivers.
- on other architectures, it is only used as part of the EFI stub,
and only for the three sysfb framebuffers (simpledrm, simplefb, efifb).
Remove the duplicate data structure definitions by moving it into the
efi-init.c file that sets it up initially for the EFI case, leaving x86
as an exception that retains its own definition for non-EFI boots.
The added #ifdefs here are optional, I added them to further limit the
reach of screen_info to configurations that have at least one of the
users enabled.
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Acked-by: Helge Deller <deller@gmx.de>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Link: https://lore.kernel.org/r/20231017093947.3627976-1-arnd@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
While adding a preferred console handling for serial_core for serial port
hardware based device addressing, Jiri suggested we constify name for
add_preferred_console(). The name gets copied anyways. This allows serial
core to add a preferred console using serial drv->dev_name without copying
it.
Note that constifying options causes changes all over the place because of
struct console for match().
Suggested-by: Jiri Slaby <jirislaby@kernel.org>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Link: https://lore.kernel.org/r/20231012064300.50221-2-tony@atomide.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Let's check for valid console index values for preferred console to avoid
bogus console index numbers from kernel command line.
Let's also return an error for negative index numbers for the preferred
console. Unlike for device drivers, a negative index is not valid for the
preferred console.
Let's also constify idx while at it.
Signed-off-by: Tony Lindgren <tony@atomide.com>
Link: https://lore.kernel.org/r/20231012064300.50221-1-tony@atomide.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The two hyperv framebuffer drivers (hyperv_fb or hyperv_drm_drv) access the
global screen_info in order to take over from the sysfb framebuffer, which
in turn could be handled by simplefb, simpledrm or efifb. Similarly, the
vmbus_drv code marks the original EFI framebuffer as reserved, but this
is not required if there is no sysfb.
As a preparation for making screen_info itself more local to the sysfb
helper code, add a compile-time conditional in all three files that relate
to hyperv fb and just skip this code if there is no sysfb that needs to
be unregistered.
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Acked-by: Helge Deller <deller@gmx.de>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Link: https://lore.kernel.org/r/20231009211845.3136536-9-arnd@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
I noticed that commit 0db5b61e0d ("fbdev/vga16fb: Create
EGA/VGA devices in sysfb code") broke vga16fb on non-x86 platforms,
because the sysfb code never creates a vga-framebuffer device when
screen_info.orig_video_isVGA is set to '1' instead of VIDEO_TYPE_VGAC.
However, it turns out that the only architecture that has allowed
building vga16fb in the past 20 years is powerpc, and this only worked
on two 32-bit platforms and never on 64-bit powerpc. The last machine
that actually used this was removed in linux-3.10, so this is all dead
code and can be removed.
The big-endian support in vga16fb.c could also be removed, but I'd just
leave this in place.
Fixes: 933ee7119f ("powerpc: remove PReP platform")
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Acked-by: Helge Deller <deller@gmx.de>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Link: https://lore.kernel.org/r/20231009211845.3136536-8-arnd@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To prepare for completely separating the VGA console screen_info from
the one used in EFI/sysfb, rename the vgacon instances and make them
local as much as possible.
ia64 and arm both have confurations with vgacon and efi, but the contents
never overlaps because ia64 has no EFI framebuffer, and arm only has
vga console on legacy platforms without EFI. Renaming these is required
before the EFI screen_info can be moved into drivers/firmware.
The ia64 vga console is actually registered in two places from
setup_arch(), but one of them is wrong, so drop the one in pcdp.c and
fix the one in setup.c to use the correct conditional.
x86 has to keep them together, as the boot protocol is used to switch
between VGA text console and framebuffer through the screen_info data.
Acked-by: Javier Martinez Canillas <javierm@redhat.com>
Acked-by: Khalid Aziz <khalid@gonehiking.org>
Acked-by: Helge Deller <deller@gmx.de>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Link: https://lore.kernel.org/r/20231009211845.3136536-7-arnd@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
A number of architectures either kept the screen_info definition for
historical purposes as it used to be required by the generic VT code, or
they copied it from another architecture in order to build the VGA console
driver in an allmodconfig build. The mips definition is used by some
platforms, but the initialization on jazz is not needed.
Now that vgacon no longer builds on these architectures, remove the
stale definitions and initializations.
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Acked-by: Dinh Nguyen <dinguyen@kernel.org>
Acked-by: Max Filippov <jcmvbkbc@gmail.com>
Acked-by: Palmer Dabbelt <palmer@rivosinc.com>
Acked-by: Guo Ren <guoren@kernel.org>
Acked-by: Helge Deller <deller@gmx.de>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Link: https://lore.kernel.org/r/20231009211845.3136536-5-arnd@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The dummycon default console size used to be determined by architecture,
but now this is a Kconfig setting on everything except ARM. Tracing this
back in the historic git trees, this was used to match the size of VGA
console or VGA framebuffer on early machines, but nowadays that code is
no longer used, except probably on the old footbridge/netwinder since
that is the only one that supports vgacon.
On machines with a framebuffer, booting with DT so far results in always
using the hardcoded 80x30 size in dummycon, while on ATAGS the setting
can come from a bootloader specific override. Both seem to be worse
choices than the Kconfig setting, since the actual text size for fbcon
also depends on the selected font.
Make this work the same way as everywhere else and use the normal
Kconfig setting, except for the footbridge with vgacon, which keeps
using the traditional code. If vgacon is disabled, footbridge can
also ignore the setting. This means the screen_info only has to be
provided when either vgacon or EFI are enabled now.
To limit the amount of surprises on Arm, change the Kconfig default
to the previously used 80x30 setting instead of the usual 80x25.
Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>
Tested-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Acked-by: Helge Deller <deller@gmx.de>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Link: https://lore.kernel.org/r/20231009211845.3136536-4-arnd@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
On non-x86 architectures, the screen_info variable is generally only
used for the VGA console where supported, and in some cases the EFI
framebuffer or vga16fb.
Now that we have a definite list of which architectures actually use it
for what, use consistent #ifdef checks so the global variable is only
defined when it is actually used on those architectures.
Loongarch and riscv have no support for vgacon or vga16fb, but
they support EFI firmware, so only that needs to be checked, and the
initialization can be removed because that is handled by EFI.
IA64 has both vgacon and EFI, though EFI apparently never uses
a framebuffer here.
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Khalid Aziz <khalid@gonehiking.org>
Acked-by: Helge Deller <deller@gmx.de>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Link: https://lore.kernel.org/r/20231009211845.3136536-3-arnd@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The list of dependencies here is phrased as an opt-out, but this is missing
a lot of architectures that don't actually support VGA consoles, and some
of the entries are stale:
- powerpc used to support VGA consoles in the old arch/ppc codebase, but
the merged arch/powerpc never did
- arm lists footbridge, integrator and netwinder, but netwinder is actually
part of footbridge, and integrator does not appear to have an actual
VGA hardware, or list it in its ATAG or DT.
- mips has a few platforms (malta, sibyte, and sni) that initialize
screen_info, on everything else the console is selected but cannot
actually work.
- csky, hexgagon, loongarch, nios2, riscv and xtensa are not listed
in the opt-out table and declare a screen_info to allow building
vga_con, but this cannot work because the console is never selected.
Replace this with an opt-in table that lists only the platforms that
remain. This is effectively x86, plus a couple of historic workstation
and server machines that reused parts of the x86 system architecture.
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Khalid Aziz <khalid@gonehiking.org>
Acked-by: Helge Deller <deller@gmx.de>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org>
Link: https://lore.kernel.org/r/20231009211845.3136536-2-arnd@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
