linux-toradex.git/drivers/tty, branch v6.16-rc4

serial: imx: Restore original RXTL for console to fix data loss

2025-06-24T14:34:21+00:00

Commit 7a637784d517 ("serial: imx: reduce RX interrupt frequency")
introduced a regression on the i.MX6UL EVK board. The issue can be
reproduced with the following steps:

- Open vi on the board.
- Paste a text file (~150 characters).
- Save the file, then repeat the process.
- Compare the sha256sum of the saved files.

The checksums do not match due to missing characters or entire lines.

Fix this by restoring the RXTL value to 1 when the UART is used as a
console.

This ensures timely RX interrupts and reliable data reception in console
mode.

With this change, pasted content is saved correctly, and checksums are
always consistent.

Cc: stable 
Fixes: 7a637784d517 ("serial: imx: reduce RX interrupt frequency")
Signed-off-by: Fabio Estevam 
Reviewed-by: Stefan Wahren 
Link: https://lore.kernel.org/r/20250619114617.2791939-1-festevam@gmail.com
Signed-off-by: Greg Kroah-Hartman

serial: core: restore of_node information in sysfs

2025-06-19T11:27:48+00:00

Since in v6.8-rc1, the of_node symlink under tty devices is
missing. This breaks any udev rules relying on this information.

Link the of_node information in the serial controller device with the
parent defined in the device tree. This will also apply to the serial
device which takes the serial controller as a parent device.

Fixes: b286f4e87e32 ("serial: core: Move tty and serdev to be children of serial core port device")
Cc: stable@vger.kernel.org
Signed-off-by: Aidan Stewart 
Link: https://lore.kernel.org/r/20250617164819.13912-1-astewart@tektelic.com
Signed-off-by: Greg Kroah-Hartman

vt: fix kernel-doc warnings in ucs_get_fallback()

2025-06-19T11:27:36+00:00

Use the correct function parameter name in ucs_get_fallback() to prevent
kernel-doc warnings:

Warning: drivers/tty/vt/ucs.c:218 function parameter 'cp' not described in 'ucs_get_fallback'
Warning: drivers/tty/vt/ucs.c:218 Excess function parameter 'base' description in 'ucs_get_fallback'

Fixes: fe26933cf1e1 ("vt: add ucs_get_fallback()")
Signed-off-by: Randy Dunlap 
Cc: Nicolas Pitre 
Cc: Greg Kroah-Hartman 
Cc: Jiri Slaby 
Cc: linux-serial@vger.kernel.org
Reviewed-by: Nicolas Pitre .
Link: https://lore.kernel.org/r/20250611020229.2650595-1-rdunlap@infradead.org
Signed-off-by: Greg Kroah-Hartman

vt: add missing notification when switching back to text mode

2025-06-19T11:27:16+00:00

Programs using poll() on /dev/vcsa to be notified when VT changes occur
were missing one case: the switch from gfx to text mode.

Signed-off-by: Nicolas Pitre 
Link: https://lore.kernel.org/r/9o5ro928-0pp4-05rq-70p4-ro385n21n723@onlyvoer.pbz
Signed-off-by: Greg Kroah-Hartman

treewide, timers: Rename from_timer() to timer_container_of()

2025-06-08T07:07:37+00:00

Move this API to the canonical timer_*() namespace.

[ tglx: Redone against pre rc1 ]

Signed-off-by: Ingo Molnar 
Signed-off-by: Thomas Gleixner 
Link: https://lore.kernel.org/all/aB2X0jCKQO56WdMt@gmail.com

tty: serial: 8250_omap: fix TX with DMA for am33xx

2025-05-22T05:50:45+00:00

Commit 1788cf6a91d9 ("tty: serial: switch from circ_buf to kfifo")
introduced an error in the TX DMA handling for 8250_omap.

When the OMAP_DMA_TX_KICK flag is set, the "skip_byte" is pulled from
the kfifo and emitted directly in order to start the DMA. While the
kfifo is updated, dma->tx_size is not decreased. This leads to
uart_xmit_advance() called in omap_8250_dma_tx_complete() advancing the
kfifo by one too much.

In practice, transmitting N bytes has been seen to result in the last
N-1 bytes being sent repeatedly.

This change fixes the problem by moving all of the dma setup after the
OMAP_DMA_TX_KICK handling and using kfifo_len() instead of the DMA size
for the 4-byte cutoff check. This slightly changes the behaviour at
buffer wraparound, but it still transmits the correct bytes somehow.

Now, the "skip_byte" would no longer be accounted to the stats. As
previously, dma->tx_size included also this skip byte, up->icount.tx was
updated by aforementioned uart_xmit_advance() in
omap_8250_dma_tx_complete(). Fix this by using the uart_fifo_out()
helper instead of bare kfifo_get().

Based on patch by Mans Rullgard 

Signed-off-by: "Jiri Slaby (SUSE)" 
Fixes: 1788cf6a91d9 ("tty: serial: switch from circ_buf to kfifo")
Link: https://lore.kernel.org/all/20250506150748.3162-1-mans@mansr.com/
Reported-by: Mans Rullgard 
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20250522053835.3495975-1-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman

vt: add VT_GETCONSIZECSRPOS to retrieve console size and cursor position

2025-05-21T11:41:03+00:00

The console dimension and cursor position are available through the
/dev/vcsa interface already. However the /dev/vcsa header format uses
single-byte fields therefore those values are clamped to 255.

As surprizing as this may seem, some people do use 240-column 67-row
screens (a 1920x1080 monitor with 8x16 pixel fonts) which is getting
close to the limit. Monitors with higher resolution are not uncommon
these days (3840x2160 producing a 480x135 character display) and it is
just a matter of time before someone with, say, a braille display using
the Linux VT console and BRLTTY on such a screen reports a bug about
missing and oddly misaligned screen content.

Let's add VT_GETCONSIZECSRPOS for the retrieval of console size and cursor
position without byte-sized limitations. The actual console size limit as
encoded in vt.c is 32767x32767 so using a short here is appropriate. Then
this can be used to get the cursor position when /dev/vcsa reports 255.

The screen dimension may already be obtained using TIOCGWINSZ and adding
the same information to VT_GETCONSIZECSRPOS might be redundant. However
applications that care about cursor position also care about display
size and having 2 separate system calls to obtain them separately is
wasteful. Also, the cursor position can be queried by writing "\e[6n" to
a tty and reading back the result but that may be done only by the actual
application using that tty and not a sideline observer.

Signed-off-by: Nicolas Pitre 
Link: https://lore.kernel.org/r/20250520171851.1219676-3-nico@fluxnic.net
Signed-off-by: Greg Kroah-Hartman

vt: bracketed paste support

2025-05-21T11:41:03+00:00

This is comprised of 3 aspects:

- Take note of when applications advertise bracketed paste support via
  "\e[?2004h" and "\e[?2004l".

- Insert bracketed paste markers ("\e[200~" and "\e[201~") around pasted
  content in paste_selection() when bracketed paste is active.

- Add TIOCL_GETBRACKETEDPASTE to return bracketed paste status so user
  space daemons implementing cut-and-paste functionality (e.g. gpm,
  BRLTTY) may know when to insert bracketed paste markers.

Link: https://en.wikipedia.org/wiki/Bracketed-paste

Signed-off-by: Nicolas Pitre 
Reviewed-by: Jiri Slaby 
Link: https://lore.kernel.org/r/20250520171851.1219676-2-nico@fluxnic.net
Signed-off-by: Greg Kroah-Hartman

vt: remove VT_RESIZE and VT_RESIZEX from vt_compat_ioctl()

2025-05-21T11:40:05+00:00

They are listed amon those cmd values that "treat 'arg' as an integer"
which is wrong. They should instead fall into the default case. Probably
nobody ever relied on that code since 2009 but still.

Fixes: e92166517e3c ("tty: handle VT specific compat ioctls in vt driver")
Signed-off-by: Nicolas Pitre 
Reviewed-by: Jiri Slaby 
Link: https://lore.kernel.org/r/pr214s15-36r8-6732-2pop-159nq85o48r7@syhkavp.arg
Signed-off-by: Greg Kroah-Hartman

vt: process the full-width ASCII fallback range programmatically

2025-05-21T11:39:45+00:00

This shaves about 170 bytes from ucs.o.

Signed-off-by: Nicolas Pitre 
Link: https://lore.kernel.org/r/20250507141535.40655-9-nico@fluxnic.net
Signed-off-by: Greg Kroah-Hartman