linux.git/drivers/tty/serial/8250, branch v6.6

serial: 8250_omap: Fix errors with no_console_suspend

2023-10-03T13:01:29+00:00

We now get errors on system suspend if no_console_suspend is set as
reported by Thomas. The errors started with commit 20a41a62618d ("serial:
8250_omap: Use force_suspend and resume for system suspend").

Let's fix the issue by checking for console_suspend_enabled in the system
suspend and resume path.

Note that with this fix the checks for console_suspend_enabled in
omap8250_runtime_suspend() become useless. We now keep runtime PM usage
count for an attached kernel console starting with commit bedb404e91bb
("serial: 8250_port: Don't use power management for kernel console").

Fixes: 20a41a62618d ("serial: 8250_omap: Use force_suspend and resume for system suspend")
Cc: stable 
Cc: Udit Kumar 
Reported-by: Thomas Richard 
Signed-off-by: Tony Lindgren 
Tested-by: Thomas Richard 
Reviewed-by: Dhruva Gole 
Link: https://lore.kernel.org/r/20230926061319.15140-1-tony@atomide.com
Signed-off-by: Greg Kroah-Hartman

serial: 8250_port: Check IRQ data before use

2023-09-18T08:05:15+00:00

In case the leaf driver wants to use IRQ polling (irq = 0) and
IIR register shows that an interrupt happened in the 8250 hardware
the IRQ data can be NULL. In such a case we need to skip the wake
event as we came to this path from the timer interrupt and quite
likely system is already awake.

Without this fix we have got an Oops:

    serial8250: ttyS0 at I/O 0x3f8 (irq = 0, base_baud = 115200) is a 16550A
    ...
    BUG: kernel NULL pointer dereference, address: 0000000000000010
    RIP: 0010:serial8250_handle_irq+0x7c/0x240
    Call Trace:
     ? serial8250_handle_irq+0x7c/0x240
     ? __pfx_serial8250_timeout+0x10/0x10

Fixes: 0ba9e3a13c6a ("serial: 8250: Add missing wakeup event reporting")
Cc: stable 
Signed-off-by: Andy Shevchenko 
Reviewed-by: Florian Fainelli 
Link: https://lore.kernel.org/r/20230831222555.614426-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Greg Kroah-Hartman

serial: 8250_bcm7271: improve bcm7271 8250 port

2023-08-22T13:30:59+00:00

The 8250 BCM7271 UART is not a direct match to PORT_16550A and other
generic ports do not match its hardware capabilities. PORT_ALTR matches
the rx trigger levels, but its vendor configurations are not compatible.
Unfortunately this means we need to create another port to fully capture
the hardware capabilities of the BCM7271 UART.

To alleviate some latency pressures, we default the rx trigger level to 8.

Signed-off-by: Justin Chen 
Reviewed-by: Florian Fainelli 
Acked-by: Doug Berger 
Reviewed-by: Andy Shevchenko 
Link: https://lore.kernel.org/r/1692643978-16570-1-git-send-email-justin.chen@broadcom.com
Signed-off-by: Greg Kroah-Hartman

serial: 8250_dw: fall back to poll if there's no interrupt

2023-08-22T13:29:29+00:00

When there's no irq(this can be due to various reasons, for example,
no irq from HW support, or we just want to use poll solution, and so
on), falling back to poll is still better than no support at all.

Signed-off-by: Jisheng Zhang 
Link: https://lore.kernel.org/r/20230806092056.2467-3-jszhang@kernel.org
Signed-off-by: Greg Kroah-Hartman

Merge commit b320441c04c9 ("Merge tag 'tty-6.5-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty") into tty-next

2023-08-20T12:29:37+00:00

We need the serial-core fixes in here as well.

Signed-off-by: Greg Kroah-Hartman

serial: 8250: drop lockdep annotation from serial8250_clear_IER()

2023-08-11T19:19:18+00:00

The port lock is not always held when calling serial8250_clear_IER().
When an oops is in progress, the lock is tried to be taken and when it
is not, a warning is issued:
 WARNING: CPU: 0 PID: 1 at drivers/tty/serial/8250/8250_port.c:707 	+0x57/0x60
 Modules linked in:
 CPU: 0 PID: 1 Comm: init Not tainted 6.5.0-rc5-1.g225bfb7-default+ #774 00f1be860db663ed29479b8255d3b01ab1135bd3
 Hardware name: QEMU Standard PC ...
 RIP: 0010:serial8250_clear_IER+0x57/0x60
...
 Call Trace:
  
  serial8250_console_write+0x9e/0x4b0
  console_flush_all+0x217/0x5f0
...

Therefore, remove the annotation as it doesn't hold for all invocations.

The other option would be to make the lockdep test conditional on
'oops_in_progress' or pass 'locked' from serial8250_console_write(). I
don't think, that is worth it.

Signed-off-by: "Jiri Slaby (SUSE)" 
Reported-by: Vlastimil Babka 
Cc: John Ogness 
Fixes: d0b309a5d3f4 (serial: 8250: synchronize and annotate UART_IER access)
Link: https://lore.kernel.org/r/20230811064340.13400-1-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman

serial: 8250: Fix oops for port->pm on uart_change_pm()

2023-08-04T15:14:38+00:00

Unloading a hardware specific 8250 driver can produce error "Unable to
handle kernel paging request at virtual address" about ten seconds after
unloading the driver. This happens on uart_hangup() calling
uart_change_pm().

Turns out commit 04e82793f068 ("serial: 8250: Reinit port->pm on port
specific driver unbind") was only a partial fix. If the hardware specific
driver has initialized port->pm function, we need to clear port->pm too.
Just reinitializing port->ops does not do this. Otherwise serial8250_pm()
will call port->pm() instead of serial8250_do_pm().

Fixes: 04e82793f068 ("serial: 8250: Reinit port->pm on port specific driver unbind")
Signed-off-by: Tony Lindgren 
Link: https://lore.kernel.org/r/20230804131553.52927-1-tony@atomide.com
Signed-off-by: Greg Kroah-Hartman

serial: 8250: Reinit port_id when adding back serial8250_isa_devs

2023-08-04T13:11:59+00:00

After fixing the serial core port device to use port->port_id instead of
port->line, unloading a hardware specific 8250 port driver started
producing an error for "sysfs: cannot create duplicate filename".

This is happening as we are wrongly initializing port->port_id to zero
when adding back serial8250_isa_devs instances, and the serial8250:0.0
sysfs entry may already exist. For serial8250 devices, we typically have
multiple devices mapped to a single driver instance. For the
serial8250_isa_devs instances, the port->port_id is the same as port->line.

Let's fix the issue by re-initializing port_id when adding back the
serial8250_isa_devs instances in serial8250_unregister_port().

Fixes: d962de6ae51f ("serial: core: Fix serial core port id to not use port->line")
Signed-off-by: Tony Lindgren 
Link: https://lore.kernel.org/r/20230804123546.25293-1-tony@atomide.com
Signed-off-by: Greg Kroah-Hartman

8250_men_mcb: remove unnecessary cast when reading register

2023-08-04T13:09:51+00:00

Fixes following sparse warning:

drivers/tty/serial/8250/8250_men_mcb.c:92:21: sparse: cast removes
    address space '__iomem' of expression
drivers/tty/serial/8250/8250_men_mcb.c:92:21: sparse: incorrect type
    in argument 1 (different address spaces) expected void const volatile
    [noderef] __iomem *addr got void *

Fixes: 2554e6ba28a2 ("8250_men_mcb: Read num ports from register data.")
Reported-by: kernel test robot 
Closes: https://lore.kernel.org/oe-kbuild-all/202307261517.x1O9OAkd-lkp@intel.com/
Signed-off-by: Jorge Sanjuan Garcia 
Link: https://lore.kernel.org/r/20230803095816.110864-1-jorge.sanjuangarcia@duagon.com
Signed-off-by: Greg Kroah-Hartman

8250_men_mcb: Remove redundant initialization owner in mcb_driver

2023-08-04T13:08:19+00:00

The module_mcb_driver() will set "THIS_MODULE" to driver.owner when
register a mcb_driver driver, so it is redundant initialization to set
driver.owner in mcb_driver statement. Remove it for clean code.

Signed-off-by: Li Zetao 
Link: https://lore.kernel.org/r/20230804100843.100348-1-lizetao1@huawei.com
Signed-off-by: Greg Kroah-Hartman