diff options
Diffstat (limited to 'debian/patches-rt/0062-serial-sprd-Use-port-lock-wrappers.patch')
| -rw-r--r-- | debian/patches-rt/0062-serial-sprd-Use-port-lock-wrappers.patch | 162 |
1 files changed, 162 insertions, 0 deletions
diff --git a/debian/patches-rt/0062-serial-sprd-Use-port-lock-wrappers.patch b/debian/patches-rt/0062-serial-sprd-Use-port-lock-wrappers.patch new file mode 100644 index 000000000..5be78db09 --- /dev/null +++ b/debian/patches-rt/0062-serial-sprd-Use-port-lock-wrappers.patch @@ -0,0 +1,162 @@ +From: Thomas Gleixner <tglx@linutronix.de> +Date: Thu, 14 Sep 2023 20:44:19 +0206 +Subject: [PATCH 062/134] serial: sprd: Use port lock wrappers +Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/6.6/older/patches-6.6.7-rt18.tar.xz + +When a serial port is used for kernel console output, then all +modifications to the UART registers which are done from other contexts, +e.g. getty, termios, are interference points for the kernel console. + +So far this has been ignored and the printk output is based on the +principle of hope. The rework of the console infrastructure which aims to +support threaded and atomic consoles, requires to mark sections which +modify the UART registers as unsafe. This allows the atomic write function +to make informed decisions and eventually to restore operational state. It +also allows to prevent the regular UART code from modifying UART registers +while printk output is in progress. + +All modifications of UART registers are guarded by the UART port lock, +which provides an obvious synchronization point with the console +infrastructure. + +To avoid adding this functionality to all UART drivers, wrap the +spin_[un]lock*() invocations for uart_port::lock into helper functions +which just contain the spin_[un]lock*() invocations for now. In a +subsequent step these helpers will gain the console synchronization +mechanisms. + +Converted with coccinelle. No functional change. + +Signed-off-by: Thomas Gleixner <tglx@linutronix.de> +Signed-off-by: John Ogness <john.ogness@linutronix.de> +Link: https://lore.kernel.org/r/20230914183831.587273-63-john.ogness@linutronix.de +Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> +Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> +--- + drivers/tty/serial/sprd_serial.c | 30 +++++++++++++++--------------- + 1 file changed, 15 insertions(+), 15 deletions(-) + +--- a/drivers/tty/serial/sprd_serial.c ++++ b/drivers/tty/serial/sprd_serial.c +@@ -247,7 +247,7 @@ static void sprd_complete_tx_dma(void *d + struct circ_buf *xmit = &port->state->xmit; + unsigned long flags; + +- spin_lock_irqsave(&port->lock, flags); ++ uart_port_lock_irqsave(port, &flags); + dma_unmap_single(port->dev, sp->tx_dma.phys_addr, + sp->tx_dma.trans_len, DMA_TO_DEVICE); + +@@ -260,7 +260,7 @@ static void sprd_complete_tx_dma(void *d + sprd_tx_dma_config(port)) + sp->tx_dma.trans_len = 0; + +- spin_unlock_irqrestore(&port->lock, flags); ++ uart_port_unlock_irqrestore(port, flags); + } + + static int sprd_uart_dma_submit(struct uart_port *port, +@@ -429,13 +429,13 @@ static void sprd_complete_rx_dma(void *d + enum dma_status status; + unsigned long flags; + +- spin_lock_irqsave(&port->lock, flags); ++ uart_port_lock_irqsave(port, &flags); + + status = dmaengine_tx_status(sp->rx_dma.chn, + sp->rx_dma.cookie, &state); + if (status != DMA_COMPLETE) { + sprd_stop_rx(port); +- spin_unlock_irqrestore(&port->lock, flags); ++ uart_port_unlock_irqrestore(port, flags); + return; + } + +@@ -449,7 +449,7 @@ static void sprd_complete_rx_dma(void *d + if (sprd_start_dma_rx(port)) + sprd_stop_rx(port); + +- spin_unlock_irqrestore(&port->lock, flags); ++ uart_port_unlock_irqrestore(port, flags); + } + + static int sprd_start_dma_rx(struct uart_port *port) +@@ -638,12 +638,12 @@ static irqreturn_t sprd_handle_irq(int i + struct uart_port *port = dev_id; + unsigned int ims; + +- spin_lock(&port->lock); ++ uart_port_lock(port); + + ims = serial_in(port, SPRD_IMSR); + + if (!ims) { +- spin_unlock(&port->lock); ++ uart_port_unlock(port); + return IRQ_NONE; + } + +@@ -660,7 +660,7 @@ static irqreturn_t sprd_handle_irq(int i + if (ims & SPRD_IMSR_TX_FIFO_EMPTY) + sprd_tx(port); + +- spin_unlock(&port->lock); ++ uart_port_unlock(port); + + return IRQ_HANDLED; + } +@@ -727,13 +727,13 @@ static int sprd_startup(struct uart_port + serial_out(port, SPRD_CTL1, fc); + + /* enable interrupt */ +- spin_lock_irqsave(&port->lock, flags); ++ uart_port_lock_irqsave(port, &flags); + ien = serial_in(port, SPRD_IEN); + ien |= SPRD_IEN_BREAK_DETECT | SPRD_IEN_TIMEOUT; + if (!sp->rx_dma.enable) + ien |= SPRD_IEN_RX_FULL; + serial_out(port, SPRD_IEN, ien); +- spin_unlock_irqrestore(&port->lock, flags); ++ uart_port_unlock_irqrestore(port, flags); + + return 0; + } +@@ -793,7 +793,7 @@ static void sprd_set_termios(struct uart + lcr |= SPRD_LCR_EVEN_PAR; + } + +- spin_lock_irqsave(&port->lock, flags); ++ uart_port_lock_irqsave(port, &flags); + + /* update the per-port timeout */ + uart_update_timeout(port, termios->c_cflag, baud); +@@ -837,7 +837,7 @@ static void sprd_set_termios(struct uart + fc |= RX_TOUT_THLD_DEF | RX_HFC_THLD_DEF; + serial_out(port, SPRD_CTL1, fc); + +- spin_unlock_irqrestore(&port->lock, flags); ++ uart_port_unlock_irqrestore(port, flags); + + /* Don't rewrite B0 */ + if (tty_termios_baud_rate(termios)) +@@ -974,9 +974,9 @@ static void sprd_console_write(struct co + if (port->sysrq) + locked = 0; + else if (oops_in_progress) +- locked = spin_trylock_irqsave(&port->lock, flags); ++ locked = uart_port_trylock_irqsave(port, &flags); + else +- spin_lock_irqsave(&port->lock, flags); ++ uart_port_lock_irqsave(port, &flags); + + uart_console_write(port, s, count, sprd_console_putchar); + +@@ -984,7 +984,7 @@ static void sprd_console_write(struct co + wait_for_xmitr(port); + + if (locked) +- spin_unlock_irqrestore(&port->lock, flags); ++ uart_port_unlock_irqrestore(port, flags); + } + + static int sprd_console_setup(struct console *co, char *options) |