linux.git/drivers/tty/serial/jsm, branch v6.12.80

serial: jsm: fix NPE during jsm_uart_port_init

2025-06-10T11:13:00+00:00

commit e3975aa899c0a3bbc10d035e699b142cd1373a71 upstream.

No device was set which caused serial_base_ctrl_add to crash.

 BUG: kernel NULL pointer dereference, address: 0000000000000050
 Oops: Oops: 0000 [#1] PREEMPT SMP NOPTI
 CPU: 16 UID: 0 PID: 368 Comm: (udev-worker) Not tainted 6.12.25-amd64 #1  Debian 6.12.25-1
 RIP: 0010:serial_base_ctrl_add+0x96/0x120
 Call Trace:
  
  serial_core_register_port+0x1a0/0x580
  ? __setup_irq+0x39c/0x660
  ? __kmalloc_cache_noprof+0x111/0x310
  jsm_uart_port_init+0xe8/0x180 [jsm]
  jsm_probe_one+0x1f4/0x410 [jsm]
  local_pci_probe+0x42/0x90
  pci_device_probe+0x22f/0x270
  really_probe+0xdb/0x340
  ? pm_runtime_barrier+0x54/0x90
  ? __pfx___driver_attach+0x10/0x10
  __driver_probe_device+0x78/0x110
  driver_probe_device+0x1f/0xa0
  __driver_attach+0xba/0x1c0
  bus_for_each_dev+0x8c/0xe0
  bus_add_driver+0x112/0x1f0
  driver_register+0x72/0xd0
  jsm_init_module+0x36/0xff0 [jsm]
  ? __pfx_jsm_init_module+0x10/0x10 [jsm]
  do_one_initcall+0x58/0x310
  do_init_module+0x60/0x230

Tested with Digi Neo PCIe 8 port card.

Fixes: 84a9582fd203 ("serial: core: Start managing serial controllers to enable runtime PM")
Cc: stable 
Signed-off-by: Dustin Lundquist 
Link: https://lore.kernel.org/r/3f31d4f75863614655c4673027a208be78d022ec.camel@null-ptr.net
Signed-off-by: Greg Kroah-Hartman

tty: serial: switch from circ_buf to kfifo

2024-04-09T13:28:03+00:00

Switch from struct circ_buf to proper kfifo. kfifo provides much better
API, esp. when wrap-around of the buffer needs to be taken into account.
Look at pl011_dma_tx_refill() or cpm_uart_tx_pump() changes for example.

Kfifo API can also fill in scatter-gather DMA structures, so it easier
for that use case too. Look at lpuart_dma_tx() for example. Note that
not all drivers can be converted to that (like atmel_serial), they
handle DMA specially.

Note that usb-serial uses kfifo for TX for ages.

omap needed a bit more care as it needs to put a char into FIFO to start
the DMA transfer when OMAP_DMA_TX_KICK is set. In that case, we have to
do kfifo_dma_out_prepare twice: once to find out the tx_size (to find
out if it is worths to do DMA at all -- size >= 4), the second time for
the actual transfer.

All traces of circ_buf are removed from serial_core.h (and its struct
uart_state).

Signed-off-by: Jiri Slaby (SUSE) 
Cc: Al Cooper 
Cc: Matthias Brugger 
Cc: AngeloGioacchino Del Regno 
Cc: Kumaravel Thiagarajan 
Cc: Tharun Kumar P 
Cc: Russell King 
Cc: Vineet Gupta 
Cc: Richard Genoud 
Cc: Nicolas Ferre 
Cc: Alexandre Belloni 
Cc: Claudiu Beznea 
Cc: Alexander Shiyan 
Cc: Baruch Siach 
Cc: Maciej W. Rozycki 
Cc: Shawn Guo 
Cc: Sascha Hauer 
Cc: Fabio Estevam 
Cc: Neil Armstrong 
Cc: Kevin Hilman 
Cc: Jerome Brunet 
Cc: Martin Blumenstingl 
Cc: Taichi Sugaya 
Cc: Takao Orito 
Cc: Bjorn Andersson 
Cc: Konrad Dybcio 
Cc: Pali Rohár 
Cc: Michael Ellerman 
Cc: Nicholas Piggin 
Cc: Christophe Leroy 
Cc: Aneesh Kumar K.V 
Cc: Naveen N. Rao 
Cc: Manivannan Sadhasivam 
Cc: Krzysztof Kozlowski 
Cc: Alim Akhtar 
Cc: Laxman Dewangan 
Cc: Thierry Reding 
Cc: Jonathan Hunter 
Cc: Orson Zhai 
Cc: Baolin Wang 
Cc: Chunyan Zhang 
Cc: Patrice Chotard 
Cc: Maxime Coquelin 
Cc: Alexandre Torgue 
Cc: David S. Miller 
Cc: Hammer Hsieh 
Cc: Peter Korsgaard 
Cc: Timur Tabi 
Cc: Michal Simek 
Cc: Sumit Semwal 
Cc: Christian König 
Link: https://lore.kernel.org/r/20240405060826.2521-13-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman

tty: jsm: Remove redundant assignment to variable linestatus

2024-02-18T17:59:58+00:00

The variable linestate being assigned a value that is never read, the
following continue statement jumps to the end of the while-loop and then
it is re-assigned a new value. The assignment is redundant and can be
removed.

Cleans up clang scan build warning:
drivers/tty/serial/jsm/jsm_cls.c:398:4: warning: Value stored
to 'linestatus' is never read [deadcode.DeadStores]

Signed-off-by: Colin Ian King 
Link: https://lore.kernel.org/r/20240216121732.2106445-1-colin.i.king@gmail.com
Signed-off-by: Greg Kroah-Hartman

tty: jsm: remove unused struct jsm_board members

2023-11-23T19:16:03+00:00

clang-struct [1] found jsm_board::type and ::jsm_board_entry unused.

::jsm_board_entry is unused since 614a7d6a76b7 ("fix up newly added jsm driver")
::type was never used as far as I can tell. Even when the driver was
introduced in the pre-git era.

Remove them both.

[1] https://github.com/jirislaby/clang-struct

Signed-off-by: "Jiri Slaby (SUSE)" 
Reviewed-by: Ilpo Järvinen 
Link: https://lore.kernel.org/r/20231121103626.17772-5-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman

tty: jsm: remove unused members from struct board_ops

2023-11-23T19:16:03+00:00

clang-struct [1] found board_ops::get_uart_bytes_left() and
::send_immediate_char() unused.

Both are only set but never called. And it has been like that since the
git history, so drop both the members along with the cls+neo
implementations.

[1] https://github.com/jirislaby/clang-struct

Signed-off-by: "Jiri Slaby (SUSE)" 
Reviewed-by: Ilpo Järvinen 
Link: https://lore.kernel.org/r/20231121103626.17772-4-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman

serial: jsm: Use port lock wrappers

2023-09-18T09:18:11+00:00

When a serial port is used for kernel console output, then all
modifications to the UART registers which are done from other contexts,
e.g. getty, termios, are interference points for the kernel console.

So far this has been ignored and the printk output is based on the
principle of hope. The rework of the console infrastructure which aims to
support threaded and atomic consoles, requires to mark sections which
modify the UART registers as unsafe. This allows the atomic write function
to make informed decisions and eventually to restore operational state. It
also allows to prevent the regular UART code from modifying UART registers
while printk output is in progress.

All modifications of UART registers are guarded by the UART port lock,
which provides an obvious synchronization point with the console
infrastructure.

To avoid adding this functionality to all UART drivers, wrap the
spin_[un]lock*() invocations for uart_port::lock into helper functions
which just contain the spin_[un]lock*() invocations for now. In a
subsequent step these helpers will gain the console synchronization
mechanisms.

Converted with coccinelle. No functional change.

Signed-off-by: Thomas Gleixner 
Signed-off-by: John Ogness 
Link: https://lore.kernel.org/r/20230914183831.587273-32-john.ogness@linutronix.de
Signed-off-by: Greg Kroah-Hartman

drivers: serial: jsm: fix some leaks in probe

2022-09-22T14:11:43+00:00

This error path needs to unwind instead of just returning directly.

Fixes: 03a8482c17dd ("drivers: serial: jsm: Enable support for Digi Classic adapters")
Signed-off-by: Dan Carpenter 
Link: https://lore.kernel.org/r/YyxFh1+lOeZ9WfKO@kili
Signed-off-by: Greg Kroah-Hartman

serial: Make ->set_termios() old ktermios const

2022-08-30T12:22:35+00:00

There should be no reason to adjust old ktermios which is going to get
discarded anyway.

Reviewed-by: Andy Shevchenko 
Signed-off-by: Ilpo Järvinen 
Link: https://lore.kernel.org/r/20220816115739.10928-7-ilpo.jarvinen@linux.intel.com
Signed-off-by: Greg Kroah-Hartman

serial: jsm: Use B0 instead of 0

2022-05-19T16:26:17+00:00

Use B0 to check zero baudrate rather than literal 0.

While at it, remove extra parenthesis around CBAUD.

Reviewed-by: Johan Hovold 
Signed-off-by: Ilpo Järvinen 
Link: https://lore.kernel.org/r/20220513082906.11096-6-ilpo.jarvinen@linux.intel.com
Signed-off-by: Greg Kroah-Hartman

tty: remove CMSPAR ifdefs

2022-05-19T16:26:16+00:00

CMSPAR is defined by all architectures since commit 6bf08cb246b5
("[PATCH] Add CMSPAR to termbits.h for powerpc and alpha").

Reviewed-by: Johan Hovold 
Signed-off-by: Ilpo Järvinen 
Link: https://lore.kernel.org/r/20220513082906.11096-2-ilpo.jarvinen@linux.intel.com
Signed-off-by: Greg Kroah-Hartman