TTY/Serial driver fixes for 6.8-rc6

Here are 3 small serial/tty driver fixes for 6.8-rc6 that resolve the
 following reported errors:
   - riscv hvc console driver fix that was reported by many
   - amba-pl011 serial driver fix for RS485 mode
   - stm32 serial driver fix for RS485 mode
 
 All of these have been in linux-next all week with no reported problems.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'tty-6.8-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty

Pull tty/serial driver fixes from Greg KH:
 "Here are three small serial/tty driver fixes for 6.8-rc6 that resolve
  the following reported errors:

   - riscv hvc console driver fix that was reported by many

   - amba-pl011 serial driver fix for RS485 mode

   - stm32 serial driver fix for RS485 mode

  All of these have been in linux-next all week with no reported
  problems"

* tag 'tty-6.8-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty:
  serial: amba-pl011: Fix DMA transmission in RS485 mode
  serial: stm32: do not always set SER_RS485_RX_DURING_TX if RS485 is enabled
  tty: hvc: Don't enable the RISC-V SBI console by default
This commit is contained in:
Linus Torvalds 2024-02-25 10:35:41 -08:00
commit 1e592e9536
3 changed files with 38 additions and 34 deletions

View File

@ -108,13 +108,15 @@ config HVC_DCC_SERIALIZE_SMP
config HVC_RISCV_SBI
bool "RISC-V SBI console support"
depends on RISCV_SBI
depends on RISCV_SBI && NONPORTABLE
select HVC_DRIVER
help
This enables support for console output via RISC-V SBI calls, which
is normally used only during boot to output printk.
is normally used only during boot to output printk. This driver
conflicts with real console drivers and should not be enabled on
systems that directly access the console.
If you don't know what do to here, say Y.
If you don't know what do to here, say N.
config HVCS
tristate "IBM Hypervisor Virtual Console Server support"

View File

@ -1339,11 +1339,41 @@ static void pl011_start_tx_pio(struct uart_amba_port *uap)
}
}
static void pl011_rs485_tx_start(struct uart_amba_port *uap)
{
struct uart_port *port = &uap->port;
u32 cr;
/* Enable transmitter */
cr = pl011_read(uap, REG_CR);
cr |= UART011_CR_TXE;
/* Disable receiver if half-duplex */
if (!(port->rs485.flags & SER_RS485_RX_DURING_TX))
cr &= ~UART011_CR_RXE;
if (port->rs485.flags & SER_RS485_RTS_ON_SEND)
cr &= ~UART011_CR_RTS;
else
cr |= UART011_CR_RTS;
pl011_write(cr, uap, REG_CR);
if (port->rs485.delay_rts_before_send)
mdelay(port->rs485.delay_rts_before_send);
uap->rs485_tx_started = true;
}
static void pl011_start_tx(struct uart_port *port)
{
struct uart_amba_port *uap =
container_of(port, struct uart_amba_port, port);
if ((uap->port.rs485.flags & SER_RS485_ENABLED) &&
!uap->rs485_tx_started)
pl011_rs485_tx_start(uap);
if (!pl011_dma_tx_start(uap))
pl011_start_tx_pio(uap);
}
@ -1424,42 +1454,12 @@ static bool pl011_tx_char(struct uart_amba_port *uap, unsigned char c,
return true;
}
static void pl011_rs485_tx_start(struct uart_amba_port *uap)
{
struct uart_port *port = &uap->port;
u32 cr;
/* Enable transmitter */
cr = pl011_read(uap, REG_CR);
cr |= UART011_CR_TXE;
/* Disable receiver if half-duplex */
if (!(port->rs485.flags & SER_RS485_RX_DURING_TX))
cr &= ~UART011_CR_RXE;
if (port->rs485.flags & SER_RS485_RTS_ON_SEND)
cr &= ~UART011_CR_RTS;
else
cr |= UART011_CR_RTS;
pl011_write(cr, uap, REG_CR);
if (port->rs485.delay_rts_before_send)
mdelay(port->rs485.delay_rts_before_send);
uap->rs485_tx_started = true;
}
/* Returns true if tx interrupts have to be (kept) enabled */
static bool pl011_tx_chars(struct uart_amba_port *uap, bool from_irq)
{
struct circ_buf *xmit = &uap->port.state->xmit;
int count = uap->fifosize >> 1;
if ((uap->port.rs485.flags & SER_RS485_ENABLED) &&
!uap->rs485_tx_started)
pl011_rs485_tx_start(uap);
if (uap->port.x_char) {
if (!pl011_tx_char(uap, uap->port.x_char, from_irq))
return true;

View File

@ -251,7 +251,9 @@ static int stm32_usart_config_rs485(struct uart_port *port, struct ktermios *ter
writel_relaxed(cr3, port->membase + ofs->cr3);
writel_relaxed(cr1, port->membase + ofs->cr1);
rs485conf->flags |= SER_RS485_RX_DURING_TX;
if (!port->rs485_rx_during_tx_gpio)
rs485conf->flags |= SER_RS485_RX_DURING_TX;
} else {
stm32_usart_clr_bits(port, ofs->cr3,
USART_CR3_DEM | USART_CR3_DEP);