linux.git/drivers/tty, branch v6.1.98 Clone of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git serial: imx: Raise TX trigger level to 8 2024-07-11T10:47:09+00:00 Matthias Schiffer matthias.schiffer@ew.tq-group.com 2024-05-08T13:37:44+00:00 e1683ff4eb68720ce1d9b4340d60ab0a6c3fd41f [ Upstream commit a3d8728ab079951741efa11360df43dbfacba7ab ] At the default TX trigger level of 2 in non-DMA mode (meaning that an interrupt is generated when less than 2 characters are left in the FIFO), we have observed frequent buffer underruns at 115200 Baud on an i.MX8M Nano. This can cause communication issues if the receiving side expects a continuous transfer. Increasing the level to 8 makes the UART trigger an interrupt earlier, giving the kernel enough time to refill the FIFO, at the cost of triggering one interrupt per ~24 instead of ~30 bytes of transmitted data (as the i.MX UART has a 32 byte FIFO). Signed-off-by: Michael Krummsdorf <michael.krummsdorf@tq-group.com> Signed-off-by: Matthias Schiffer <matthias.schiffer@ew.tq-group.com> Link: https://lore.kernel.org/r/20240508133744.35858-1-matthias.schiffer@ew.tq-group.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit a3d8728ab079951741efa11360df43dbfacba7ab ]

At the default TX trigger level of 2 in non-DMA mode (meaning that an
interrupt is generated when less than 2 characters are left in the
FIFO), we have observed frequent buffer underruns at 115200 Baud on an
i.MX8M Nano. This can cause communication issues if the receiving side
expects a continuous transfer.

Increasing the level to 8 makes the UART trigger an interrupt earlier,
giving the kernel enough time to refill the FIFO, at the cost of
triggering one interrupt per ~24 instead of ~30 bytes of transmitted
data (as the i.MX UART has a 32 byte FIFO).

Signed-off-by: Michael Krummsdorf <michael.krummsdorf@tq-group.com>
Signed-off-by: Matthias Schiffer <matthias.schiffer@ew.tq-group.com>
Link: https://lore.kernel.org/r/20240508133744.35858-1-matthias.schiffer@ew.tq-group.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
serial: 8250_omap: Fix Errata i2310 with RX FIFO level check 2024-07-05T07:32:01+00:00 Udit Kumar u-kumar1@ti.com 2024-06-25T16:07:25+00:00 fbfd2c876c431f28a99a94a92a2183ca896c0c8f commit c128a1b0523b685c8856ddc0ac0e1caef1fdeee5 upstream. Errata i2310[0] says, Erroneous timeout can be triggered, if this Erroneous interrupt is not cleared then it may leads to storm of interrupts. Commit 9d141c1e6157 ("serial: 8250_omap: Implementation of Errata i2310") which added the workaround but missed ensuring RX FIFO is really empty before applying the errata workaround as recommended in the errata text. Fix this by adding back check for UART_OMAP_RX_LVL to be 0 for workaround to take effect. [0] https://www.ti.com/lit/pdf/sprz536 page 23 Fixes: 9d141c1e6157 ("serial: 8250_omap: Implementation of Errata i2310") Cc: stable@vger.kernel.org Reported-by: Vignesh Raghavendra <vigneshr@ti.com> Closes: https://lore.kernel.org/all/e96d0c55-0b12-4cbf-9d23-48963543de49@ti.com/ Signed-off-by: Udit Kumar <u-kumar1@ti.com> Link: https://lore.kernel.org/r/20240625160725.2102194-1-u-kumar1@ti.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit c128a1b0523b685c8856ddc0ac0e1caef1fdeee5 upstream.

Errata i2310[0] says, Erroneous timeout can be triggered,
if this Erroneous interrupt is not cleared then it may leads
to storm of interrupts.

Commit 9d141c1e6157 ("serial: 8250_omap: Implementation of Errata i2310")
which added the workaround but missed ensuring RX FIFO is really empty
before applying the errata workaround as recommended in the errata text.
Fix this by adding back check for UART_OMAP_RX_LVL to be 0 for
workaround to take effect.

[0] https://www.ti.com/lit/pdf/sprz536 page 23

Fixes: 9d141c1e6157 ("serial: 8250_omap: Implementation of Errata i2310")
Cc: stable@vger.kernel.org
Reported-by: Vignesh Raghavendra <vigneshr@ti.com>
Closes: https://lore.kernel.org/all/e96d0c55-0b12-4cbf-9d23-48963543de49@ti.com/
Signed-off-by: Udit Kumar <u-kumar1@ti.com>
Link: https://lore.kernel.org/r/20240625160725.2102194-1-u-kumar1@ti.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
serial: imx: only set receiver level if it is zero 2024-07-05T07:32:01+00:00 Stefan Eichenberger stefan.eichenberger@toradex.com 2024-07-03T11:25:40+00:00 1dc9d050409baa952f82ca62f479a04e09ee74d7 commit 9706fc87b4cff0ac4f5d5d62327be83fe72e3108 upstream. With commit a81dbd0463ec ("serial: imx: set receiver level before starting uart") we set the receiver level to its default value. This caused a regression when using SDMA, where the receiver level is 9 instead of 8 (default). This change will first check if the receiver level is zero and only then set it to the default. This still avoids the interrupt storm when the receiver level is zero. Fixes: a81dbd0463ec ("serial: imx: set receiver level before starting uart") Cc: stable <stable@kernel.org> Signed-off-by: Stefan Eichenberger <stefan.eichenberger@toradex.com> Link: https://lore.kernel.org/r/20240703112543.148304-1-eichest@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 9706fc87b4cff0ac4f5d5d62327be83fe72e3108 upstream.

With commit a81dbd0463ec ("serial: imx: set receiver level before
starting uart") we set the receiver level to its default value. This
caused a regression when using SDMA, where the receiver level is 9
instead of 8 (default). This change will first check if the receiver
level is zero and only then set it to the default. This still avoids the
interrupt storm when the receiver level is zero.

Fixes: a81dbd0463ec ("serial: imx: set receiver level before starting uart")
Cc: stable <stable@kernel.org>
Signed-off-by: Stefan Eichenberger <stefan.eichenberger@toradex.com>
Link: https://lore.kernel.org/r/20240703112543.148304-1-eichest@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
tty: mcf: MCF54418 has 10 UARTS 2024-07-05T07:31:56+00:00 Jean-Michel Hautbois jeanmichel.hautbois@yoseli.org 2024-06-20T16:29:59+00:00 a44aedd5123792f4f094ecc0ffa114a109f73c07 commit 7c92a8bd53f24d50c8cf4aba53bb75505b382fed upstream. Most of the colfires have up to 5 UARTs but MCF54418 has up-to 10 ! Change the maximum value authorized. Signed-off-by: Jean-Michel Hautbois <jeanmichel.hautbois@yoseli.org> Cc: stable <stable@kernel.org> Fixes: 2545cf6e94b4 ("m68knommu: allow 4 coldfire serial ports") Link: https://lore.kernel.org/r/20240620-upstream-uart-v1-1-a9d0d95fb19e@yoseli.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 7c92a8bd53f24d50c8cf4aba53bb75505b382fed upstream.

Most of the colfires have up to 5 UARTs but MCF54418 has up-to 10 !
Change the maximum value authorized.

Signed-off-by: Jean-Michel Hautbois <jeanmichel.hautbois@yoseli.org>
Cc: stable <stable@kernel.org>
Fixes: 2545cf6e94b4 ("m68knommu: allow 4 coldfire serial ports")
Link: https://lore.kernel.org/r/20240620-upstream-uart-v1-1-a9d0d95fb19e@yoseli.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
serial: imx: set receiver level before starting uart 2024-07-05T07:31:55+00:00 Stefan Eichenberger stefan.eichenberger@toradex.com 2024-06-21T15:37:49+00:00 e97ef9a3a31f481bf7618572996366047089c43e commit a81dbd0463eca317eee44985a66aa6cc2ce5c101 upstream. Set the receiver level to something > 0 before calling imx_uart_start_rx in rs485_config. This is necessary to avoid an interrupt storm that might prevent the system from booting. This was seen on an i.MX7 device when the rs485-rts-active-low property was active in the device tree. Fixes: 6d215f83e5fc ("serial: imx: warn user when using unsupported configuration") Cc: stable <stable@kernel.org> Signed-off-by: Stefan Eichenberger <stefan.eichenberger@toradex.com> Link: https://lore.kernel.org/r/20240621153829.183780-1-eichest@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit a81dbd0463eca317eee44985a66aa6cc2ce5c101 upstream.

Set the receiver level to something > 0 before calling imx_uart_start_rx
in rs485_config. This is necessary to avoid an interrupt storm that
might prevent the system from booting. This was seen on an i.MX7 device
when the rs485-rts-active-low property was active in the device tree.

Fixes: 6d215f83e5fc ("serial: imx: warn user when using unsupported configuration")
Cc: stable <stable@kernel.org>
Signed-off-by: Stefan Eichenberger <stefan.eichenberger@toradex.com>
Link: https://lore.kernel.org/r/20240621153829.183780-1-eichest@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
serial: 8250_omap: Implementation of Errata i2310 2024-07-05T07:31:55+00:00 Udit Kumar u-kumar1@ti.com 2024-06-19T10:59:03+00:00 98840e410d53329f5331ecdce095e740791963d0 commit 9d141c1e615795eeb93cd35501ad144ee997a826 upstream. As per Errata i2310[0], Erroneous timeout can be triggered, if this Erroneous interrupt is not cleared then it may leads to storm of interrupts, therefore apply Errata i2310 solution. [0] https://www.ti.com/lit/pdf/sprz536 page 23 Fixes: b67e830d38fa ("serial: 8250: 8250_omap: Fix possible interrupt storm on K3 SoCs") Cc: stable@vger.kernel.org Signed-off-by: Udit Kumar <u-kumar1@ti.com> Link: https://lore.kernel.org/r/20240619105903.165434-1-u-kumar1@ti.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 9d141c1e615795eeb93cd35501ad144ee997a826 upstream.

As per Errata i2310[0], Erroneous timeout can be triggered,
if this Erroneous interrupt is not cleared then it may leads
to storm of interrupts, therefore apply Errata i2310 solution.

[0] https://www.ti.com/lit/pdf/sprz536 page 23

Fixes: b67e830d38fa ("serial: 8250: 8250_omap: Fix possible interrupt storm on K3 SoCs")
Cc: stable@vger.kernel.org
Signed-off-by: Udit Kumar <u-kumar1@ti.com>
Link: https://lore.kernel.org/r/20240619105903.165434-1-u-kumar1@ti.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
tty: add the option to have a tty reject a new ldisc 2024-06-27T11:46:17+00:00 Linus Torvalds torvalds@linux-foundation.org 2024-04-23T16:33:39+00:00 3c6332f3bb1578b5b10ac2561247b1d6272ae937 [ Upstream commit 6bd23e0c2bb6c65d4f5754d1456bc9a4427fc59b ] ... and use it to limit the virtual terminals to just N_TTY. They are kind of special, and in particular, the "con_write()" routine violates the "writes cannot sleep" rule that some ldiscs rely on. This avoids the BUG: sleeping function called from invalid context at kernel/printk/printk.c:2659 when N_GSM has been attached to a virtual console, and gsmld_write() calls con_write() while holding a spinlock, and con_write() then tries to get the console lock. Tested-by: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp> Cc: Jiri Slaby <jirislaby@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Daniel Starke <daniel.starke@siemens.com> Reported-by: syzbot <syzbot+dbac96d8e73b61aa559c@syzkaller.appspotmail.com> Closes: https://syzkaller.appspot.com/bug?extid=dbac96d8e73b61aa559c Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Link: https://lore.kernel.org/r/20240423163339.59780-1-torvalds@linux-foundation.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 6bd23e0c2bb6c65d4f5754d1456bc9a4427fc59b ]

... and use it to limit the virtual terminals to just N_TTY.  They are
kind of special, and in particular, the "con_write()" routine violates
the "writes cannot sleep" rule that some ldiscs rely on.

This avoids the

   BUG: sleeping function called from invalid context at kernel/printk/printk.c:2659

when N_GSM has been attached to a virtual console, and gsmld_write()
calls con_write() while holding a spinlock, and con_write() then tries
to get the console lock.

Tested-by: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Cc: Jiri Slaby <jirislaby@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Daniel Starke <daniel.starke@siemens.com>
Reported-by: syzbot <syzbot+dbac96d8e73b61aa559c@syzkaller.appspotmail.com>
Closes: https://syzkaller.appspot.com/bug?extid=dbac96d8e73b61aa559c
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lore.kernel.org/r/20240423163339.59780-1-torvalds@linux-foundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
serial: exar: adding missing CTI and Exar PCI ids 2024-06-27T11:46:17+00:00 Parker Newman pnewman@connecttech.com 2024-04-16T12:55:28+00:00 3b3655a1d3a4ed621ee5c4fe1d9b833b74d92f59 [ Upstream commit b86ae40ffcf5a16b9569b1016da4a08c4f352ca2 ] - Added Connect Tech and Exar IDs not already in pci_ids.h Signed-off-by: Parker Newman <pnewman@connecttech.com> Link: https://lore.kernel.org/r/7c3d8e795a864dd9b0a00353b722060dc27c4e09.1713270624.git.pnewman@connecttech.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit b86ae40ffcf5a16b9569b1016da4a08c4f352ca2 ]

- Added Connect Tech and Exar IDs not already in pci_ids.h

Signed-off-by: Parker Newman <pnewman@connecttech.com>
Link: https://lore.kernel.org/r/7c3d8e795a864dd9b0a00353b722060dc27c4e09.1713270624.git.pnewman@connecttech.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
serial: imx: Introduce timeout when waiting on transmitter empty 2024-06-27T11:46:17+00:00 Esben Haabendal esben@geanix.com 2024-04-11T12:19:23+00:00 7f9e70c68b7ace0141fe3bc94bf7b61296b71916 [ Upstream commit e533e4c62e9993e62e947ae9bbec34e4c7ae81c2 ] By waiting at most 1 second for USR2_TXDC to be set, we avoid a potential deadlock. In case of the timeout, there is not much we can do, so we simply ignore the transmitter state and optimistically try to continue. Signed-off-by: Esben Haabendal <esben@geanix.com> Acked-by: Marc Kleine-Budde <mkl@pengutronix.de> Link: https://lore.kernel.org/r/919647898c337a46604edcabaf13d42d80c0915d.1712837613.git.esben@geanix.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit e533e4c62e9993e62e947ae9bbec34e4c7ae81c2 ]

By waiting at most 1 second for USR2_TXDC to be set, we avoid a potential
deadlock.

In case of the timeout, there is not much we can do, so we simply ignore
the transmitter state and optimistically try to continue.

Signed-off-by: Esben Haabendal <esben@geanix.com>
Acked-by: Marc Kleine-Budde <mkl@pengutronix.de>
Link: https://lore.kernel.org/r/919647898c337a46604edcabaf13d42d80c0915d.1712837613.git.esben@geanix.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
serial: 8250_dw: fall back to poll if there's no interrupt 2024-06-21T12:36:00+00:00 Jisheng Zhang jszhang@kernel.org 2023-08-06T09:20:56+00:00 29d35f0b53d4bd82ebc37c500a8dd73da61318ff [ Upstream commit 22130dae0533c474e4e0db930a88caa9b397d083 ] 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 <jszhang@kernel.org> Link: https://lore.kernel.org/r/20230806092056.2467-3-jszhang@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Stable-dep-of: 87d80bfbd577 ("serial: 8250_dw: Don't use struct dw8250_data outside of 8250_dw") Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 22130dae0533c474e4e0db930a88caa9b397d083 ]

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 <jszhang@kernel.org>
Link: https://lore.kernel.org/r/20230806092056.2467-3-jszhang@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Stable-dep-of: 87d80bfbd577 ("serial: 8250_dw: Don't use struct dw8250_data outside of 8250_dw")
Signed-off-by: Sasha Levin <sashal@kernel.org>