linux.git/drivers/tty/serial/8250, branch v5.13

serial: 8250_exar: Avoid NULL pointer dereference at ->exit()

2021-06-09T12:40:48+00:00

It's possible that during ->exit() the private_data is NULL,
for instance when there was no GPIO device instantiated.
Due to this we may not dereference it. Add a respective check.

Note, for now ->exit() only makes sense when GPIO device
was instantiated, that's why we may use the check for entire
function.

Fixes: 81171e7d31a6 ("serial: 8250_exar: Constify the software nodes")
Reported-by: Maxim Levitsky 
Signed-off-by: Andy Shevchenko 
Tested-by: Maxim Levitsky 
Link: https://lore.kernel.org/r/20210608144239.12697-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Greg Kroah-Hartman

Revert "serial: 8250: 8250_omap: Fix possible interrupt storm"

2021-05-28T08:58:49+00:00

This reverts commit 31fae7c8b18c3f8029a2a5dce97a3182c1a167a0.

Tony writes:
	I just noticed this causes the following regression in Linux
	next when pressing a key on uart console after boot at least on
	omap3. This seems to happen on serial_port_in(port, UART_RX) in
	the quirk handling.

So let's drop this.

Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/YLCCJzkkB4N7LTQS@atomide.com
Fixes: 31fae7c8b18c ("serial: 8250: 8250_omap: Fix possible interrupt storm")
Reported-by: Tony Lindgren 
Cc: Jan Kiszka 
Cc: Vignesh Raghavendra 
Signed-off-by: Greg Kroah-Hartman

serial: 8250_pci: handle FL_NOIRQ board flag

2021-05-27T13:22:36+00:00

In commit 8428413b1d14 ("serial: 8250_pci: Implement MSI(-X) support")
the way the irq gets allocated was changed. With that change the
handling FL_NOIRQ got lost. Restore the old behaviour.

Fixes: 8428413b1d14 ("serial: 8250_pci: Implement MSI(-X) support")
Cc: 
Signed-off-by: Christian Gmeiner 
Link: https://lore.kernel.org/r/20210527095529.26281-1-christian.gmeiner@gmail.com
Signed-off-by: Greg Kroah-Hartman

serial: 8250_pci: Add support for new HPE serial device

2021-05-20T15:17:16+00:00

Add support for new HPE serial device.  It is MSI enabled,
but otherwise similar to legacy HP server serial devices.

Tested-by: Jerry Hoemann 
Signed-off-by: Randy Wright 
Cc: stable 
Link: https://lore.kernel.org/r/1621009614-28836-1-git-send-email-rwright@hpe.com
Signed-off-by: Greg Kroah-Hartman

serial: 8250: 8250_omap: Fix possible interrupt storm

2021-05-20T15:16:55+00:00

It is possible that RX TIMEOUT is signalled after RX FIFO has been
drained, in which case a dummy read of RX FIFO is required to clear RX
TIMEOUT condition. Otherwise, RX TIMEOUT condition is not cleared
leading to an interrupt storm

Cc: stable@vger.kernel.org
Reported-by: Jan Kiszka 
Signed-off-by: Vignesh Raghavendra 
Link: https://lore.kernel.org/r/20210511151955.28071-1-vigneshr@ti.com
Signed-off-by: Greg Kroah-Hartman

serial: 8250: Use BIT(x) for UART_{CAP,BUG}_*

2021-05-20T15:14:50+00:00

BIT(x) improves readability and safety with respect to shifts.

Reviewed-by: Jiri Slaby 
Signed-off-by: Andrew Jeffery 
Link: https://lore.kernel.org/r/20210520021334.497341-3-andrew@aj.id.au
Signed-off-by: Greg Kroah-Hartman

serial: 8250: Add UART_BUG_TXRACE workaround for Aspeed VUART

2021-05-20T15:14:46+00:00

Aspeed Virtual UARTs directly bridge e.g. the system console UART on the
LPC bus to the UART interface on the BMC's internal APB. As such there's
no RS-232 signalling involved - the UART interfaces on each bus are
directly connected as the producers and consumers of the one set of
FIFOs.

The APB in the AST2600 generally runs at 100MHz while the LPC bus peaks
at 33MHz. The difference in clock speeds exposes a race in the VUART
design where a Tx data burst on the APB interface can result in a byte
lost on the LPC interface. The symptom is LSR[DR] remains clear on the
LPC interface despite data being present in its Rx FIFO, while LSR[THRE]
remains clear on the APB interface as the host has not consumed the data
the BMC has transmitted. In this state, the UART has stalled and no
further data can be transmitted without manual intervention (e.g.
resetting the FIFOs, resulting in loss of data).

The recommended work-around is to insert a read cycle on the APB
interface between writes to THR.

Cc: ChiaWei Wang 
Tested-by: ChiaWei Wang 
Reviewed-by: Jiri Slaby 
Signed-off-by: Andrew Jeffery 
Cc: stable 
Link: https://lore.kernel.org/r/20210520021334.497341-2-andrew@aj.id.au
Signed-off-by: Greg Kroah-Hartman

serial: 8250_dw: Add device HID for new AMD UART controller

2021-05-13T15:08:42+00:00

Add device HID AMDI0022 to the AMD UART controller driver match table
and create a platform device for it. This controller can be found on
Microsoft Surface Laptop 4 devices and seems similar enough that we can
just copy the existing AMDI0020 entries.

Cc:  # 5.10+
Tested-by: Sachi King 
Acked-by: Andy Shevchenko  # for 8250_dw part
Signed-off-by: Maximilian Luz 
Link: https://lore.kernel.org/r/20210512210413.1982933-1-luzmaximilian@gmail.com
Signed-off-by: Greg Kroah-Hartman

serial: extend compile-test coverage

2021-04-22T11:12:13+00:00

Allow more drivers to be compile tested more easily, for example, when
doing subsystem-wide changes.

Verified on X86_64 as well as arm, powerpc and m68k with minimal configs
in order to catch missing implicit build dependencies (e.g. MAILBOX for
SERIAL_TEGRA_TCU).

Signed-off-by: Johan Hovold 
Link: https://lore.kernel.org/r/20210422080211.29326-1-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman

serial: do not restore interrupt state in sysrq helper

2021-04-22T10:04:26+00:00

The uart_unlock_and_check_sysrq() helper can be used to defer processing
of sysrq until the interrupt handler has released the port lock and is
about to return.

Since commit 81e2073c175b ("genirq: Disable interrupts for force
threaded handlers") interrupt handlers that are not explicitly requested
as threaded are always called with interrupts disabled and there is no
need to save the interrupt state when taking the port lock.

Instead of adding another sysrq helper for when the interrupt state has
not needlessly been saved, drop the state parameter from
uart_unlock_and_check_sysrq() and update its callers to no longer
explicitly disable interrupts in their interrupt handlers.

Cc: Joel Stanley 
Cc: Andrew Jeffery 
Cc: Andy Gross 
Cc: Bjorn Andersson 
Signed-off-by: Johan Hovold 
Link: https://lore.kernel.org/r/20210416140557.25177-2-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman