[ Upstream commit 8be3a7bf77 ]
As comment of pci_get_slot() says, it returns a pci_device with its
refcount increased. The caller must decrement the reference count by
calling pci_dev_put().
Since 'dma_dev' is only used to filter the channel in filter(), we can
call pci_dev_put() before exiting from pch_request_dma(). Add the
missing pci_dev_put() for the normal and error path.
Fixes: 3c6a483275 ("Serial: EG20T: add PCH_UART driver")
Signed-off-by: Xiongfeng Wang <wangxiongfeng2@huawei.com>
Link: https://lore.kernel.org/r/20221122114559.27692-1-wangxiongfeng2@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 94cdb9f336 ]
Chapter "B Generic UART" in "ARM Server Base System Architecture" [1]
documentation describes a generic UART interface. Such generic UART
does not support DMA. In current code, sbsa_uart_pops and
amba_pl011_pops share the same stop_rx operation, which will invoke
pl011_dma_rx_stop, leading to an access of the DMACR register. This
commit adds a using_rx_dma check in pl011_dma_rx_stop to avoid the
access to DMACR register for SBSA UARTs which does not support DMA.
When the kernel enables DMA engine with "CONFIG_DMA_ENGINE=y", Linux
SBSA PL011 driver will access PL011 DMACR register in some functions.
For most real SBSA Pl011 hardware implementations, the DMACR write
behaviour will be ignored. So these DMACR operations will not cause
obvious problems. But for some virtual SBSA PL011 hardware, like Xen
virtual SBSA PL011 (vpl011) device, the behaviour might be different.
Xen vpl011 emulation will inject a data abort to guest, when guest is
accessing an unimplemented UART register. As Xen VPL011 is SBSA
compatible, it will not implement DMACR register. So when Linux SBSA
PL011 driver access DMACR register, it will get an unhandled data abort
fault and the application will get a segmentation fault:
Unhandled fault at 0xffffffc00944d048
Mem abort info:
ESR = 0x96000000
EC = 0x25: DABT (current EL), IL = 32 bits
SET = 0, FnV = 0
EA = 0, S1PTW = 0
FSC = 0x00: ttbr address size fault
Data abort info:
ISV = 0, ISS = 0x00000000
CM = 0, WnR = 0
swapper pgtable: 4k pages, 39-bit VAs, pgdp=0000000020e2e000
[ffffffc00944d048] pgd=100000003ffff803, p4d=100000003ffff803, pud=100000003ffff803, pmd=100000003fffa803, pte=006800009c090f13
Internal error: ttbr address size fault: 96000000 [#1] PREEMPT SMP
...
Call trace:
pl011_stop_rx+0x70/0x80
tty_port_shutdown+0x7c/0xb4
tty_port_close+0x60/0xcc
uart_close+0x34/0x8c
tty_release+0x144/0x4c0
__fput+0x78/0x220
____fput+0x1c/0x30
task_work_run+0x88/0xc0
do_notify_resume+0x8d0/0x123c
el0_svc+0xa8/0xc0
el0t_64_sync_handler+0xa4/0x130
el0t_64_sync+0x1a0/0x1a4
Code: b9000083 b901f001 794038a0 8b000042 (b9000041)
---[ end trace 83dd93df15c3216f ]---
note: bootlogd[132] exited with preempt_count 1
/etc/rcS.d/S07bootlogd: line 47: 132 Segmentation fault start-stop-daemon
This has been discussed in the Xen community, and we think it should fix
this in Linux. See [2] for more information.
[1] https://developer.arm.com/documentation/den0094/c/?lang=en
[2] https://lists.xenproject.org/archives/html/xen-devel/2022-11/msg00543.html
Fixes: 0dd1e247fd (drivers: PL011: add support for the ARM SBSA generic UART)
Signed-off-by: Jiamei Xie <jiamei.xie@arm.com>
Reviewed-by: Andre Przywara <andre.przywara@arm.com>
Link: https://lore.kernel.org/r/20221117103237.86856-1-jiamei.xie@arm.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 038ee49fef ]
RS485-enabled UART ports on TI Sitara SoCs with active-low polarity
exhibit a Transmit Enable glitch on ->set_termios():
omap8250_restore_regs(), which is called from omap_8250_set_termios(),
sets the TCRTLR bit in the MCR register and clears all other bits,
including RTS. If RTS uses active-low polarity, it is now asserted
for no reason.
The TCRTLR bit is subsequently cleared by writing up->mcr to the MCR
register. That variable is always zero, so the RTS bit is still cleared
(incorrectly so if RTS is active-high).
(up->mcr is not, as one might think, a cache of the MCR register's
current value. Rather, it only caches a single bit of that register,
the AFE bit. And it only does so if the UART supports the AFE bit,
which OMAP does not. For details see serial8250_do_set_termios() and
serial8250_do_set_mctrl().)
Finally at the end of omap8250_restore_regs(), the MCR register is
restored (and RTS deasserted) by a call to up->port.ops->set_mctrl()
(which equals serial8250_set_mctrl()) and serial8250_em485_stop_tx().
So there's an RTS glitch between setting TCRTLR and calling
serial8250_em485_stop_tx(). Avoid by using a read-modify-write
when setting TCRTLR.
While at it, drop a redundant initialization of up->mcr. As explained
above, the variable isn't used by the driver and it is already
initialized to zero because it is part of the static struct
serial8250_ports[] declared in 8250_core.c. (Static structs are
initialized to zero per section 6.7.8 nr. 10 of the C99 standard.)
Cc: Jan Kiszka <jan.kiszka@siemens.com>
Cc: Su Bao Cheng <baocheng.su@siemens.com>
Tested-by: Matthias Schiffer <matthias.schiffer@ew.tq-group.com>
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Link: https://lore.kernel.org/r/6554b0241a2c7fd50f32576fdbafed96709e11e8.1664278942.git.lukas@wunner.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit d0b68629bd ]
Rebinding 8250_omap in a loop will at some point produce a warning for
kernel/power/qos.c:296 cpu_latency_qos_update_request() with error
"cpu_latency_qos_update_request called for unknown object". Let's flush
the possibly pending PM QOS work scheduled from omap8250_runtime_suspend()
before we disable runtime PM.
Fixes: 61929cf016 ("tty: serial: Add 8250-core based omap driver")
Signed-off-by: Tony Lindgren <tony@atomide.com>
Link: https://lore.kernel.org/r/20221028110044.54719-1-tony@atomide.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit e828e56684 ]
We were occasionally seeing the "Errata i202: timedout" on an AM335x
board when repeatedly opening and closing a UART connected to an active
sender. As new input may arrive at any time, it is possible to miss the
"RX FIFO empty" condition, forcing the loop to wait until it times out.
Nothing in the i202 Advisory states that such a wait is even necessary;
other FIFO clear functions like serial8250_clear_fifos() do not wait
either. For this reason, it seems safe to remove the wait, fixing the
mentioned issue.
Fixes: 61929cf016 ("tty: serial: Add 8250-core based omap driver")
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Matthias Schiffer <matthias.schiffer@ew.tq-group.com>
Link: https://lore.kernel.org/r/20221013112339.2540767-1-matthias.schiffer@ew.tq-group.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit e8a18e3f00 upstream.
Although the name of the driver 8250_gsc.c suggests that it handles
only serial ports on the GSC bus, it does handle serial ports listed
in the parisc machine inventory as well, e.g. the serial ports in a
C8000 PCI-only workstation.
Change the dependency to CONFIG_PARISC, so that the driver gets included
in the kernel even if CONFIG_GSC isn't set.
Reported-by: Mikulas Patocka <mpatocka@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 379a33786d ]
Since commit edc6afc549 ("tty: switch to ktermios and new framework")
termios speed is no longer stored only in c_cflag member but also in new
additional c_ispeed and c_ospeed members. If BOTHER flag is set in c_cflag
then termios speed is stored only in these new members.
Since commit 027b57170b ("serial: core: Fix initializing and restoring
termios speed") termios speed is available also in struct console.
So properly restore also c_ispeed and c_ospeed members after suspend to fix
restoring termios speed which is not represented by Bnnn constant.
Fixes: 4516d50aab ("serial: 8250: Use canary to restart console after suspend")
Signed-off-by: Pali Rohár <pali@kernel.org>
Link: https://lore.kernel.org/r/20220924104324.4035-1-pali@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 6e690d54cf upstream.
If port->mapbase = NULL in serial8250_request_std_resource() , it need
return a error code instead of 0. If uart_set_info() fail to request new
regions by serial8250_request_std_resource() but the return value of
serial8250_request_std_resource() is 0, The system incorrectly considers
that the resource application is successful and does not attempt to
restore the old setting. A null pointer reference is triggered when the
port resource is later invoked.
Signed-off-by: Yi Yang <yiyang13@huawei.com>
Cc: stable <stable@kernel.org>
Link: https://lore.kernel.org/r/20220628083515.64138-1-yiyang13@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 62b2caef40 ]
There is a deadlock in sa1100_set_termios(), which is shown
below:
(Thread 1) | (Thread 2)
| sa1100_enable_ms()
sa1100_set_termios() | mod_timer()
spin_lock_irqsave() //(1) | (wait a time)
... | sa1100_timeout()
del_timer_sync() | spin_lock_irqsave() //(2)
(wait timer to stop) | ...
We hold sport->port.lock in position (1) of thread 1 and
use del_timer_sync() to wait timer to stop, but timer handler
also need sport->port.lock in position (2) of thread 2. As a result,
sa1100_set_termios() will block forever.
This patch moves del_timer_sync() before spin_lock_irqsave()
in order to prevent the deadlock.
Signed-off-by: Duoming Zhou <duoming@zju.edu.cn>
Link: https://lore.kernel.org/r/20220417111626.7802-1-duoming@zju.edu.cn
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 589f892ac8 ]
The uart_ops startup() callback is called without interrupts
disabled and without port->lock locked, relatively late during the
boot process (from the call path of console_on_rootfs()). If the
device is a console, it was already previously registered and could
be actively printing messages.
Since the startup() callback is reading/writing registers used by
the console write() callback (AML_UART_CONTROL), its access must
be synchronized using the port->lock. Currently it is not.
The startup() callback is the only function that explicitly enables
interrupts. Without the synchronization, it is possible that
interrupts become accidentally permanently disabled.
CPU0 CPU1
meson_serial_console_write meson_uart_startup
-------------------------- ------------------
spin_lock(port->lock)
val = readl(AML_UART_CONTROL)
uart_console_write()
writel(INT_EN, AML_UART_CONTROL)
writel(val, AML_UART_CONTROL)
spin_unlock(port->lock)
Add port->lock synchronization to meson_uart_startup() to avoid
racing with meson_serial_console_write().
Also add detailed comments to meson_uart_reset() explaining why it
is *not* using port->lock synchronization.
Link: https://lore.kernel.org/lkml/2a82eae7-a256-f70c-fd82-4e510750906e@samsung.com
Fixes: ff7693d079 ("ARM: meson: serial: add MesonX SoC on-chip uart driver")
Reported-by: Marek Szyprowski <m.szyprowski@samsung.com>
Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Reviewed-by: Jiri Slaby <jirislaby@kernel.org>
Acked-by: Neil Armstrong <narmstrong@baylibre.com>
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Link: https://lore.kernel.org/r/20220508103547.626355-1-john.ogness@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 637674fa40 upstream.
The EndRun PTP/1588 dual serial port device is based on the Oxford
Semiconductor OXPCIe952 UART device with the PCI vendor:device ID set
for EndRun Technologies and is therefore driven by a fixed 62.5MHz clock
input derived from the 100MHz PCI Express clock. The clock rate is
divided by the oversampling rate of 16 as it is supplied to the baud
rate generator, yielding the baud base of 3906250.
Replace the incorrect baud base of 4000000 with the right value of
3906250 then, complementing commit 6cbe45d8ac ("serial: 8250: Correct
the clock for OxSemi PCIe devices").
Signed-off-by: Maciej W. Rozycki <macro@orcam.me.uk>
Cc: stable <stable@kernel.org>
Fixes: 1bc8cde46a ("8250_pci: Added driver for Endrun Technologies PTP PCIe card.")
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/alpine.DEB.2.21.2204181515270.9383@angie.orcam.me.uk
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
