From 35c955b5a45ec8817d37a7ac46d0d2e2d510f8ec Mon Sep 17 00:00:00 2001 From: Randy Dunlap Date: Mon, 14 Feb 2022 10:00:19 -0800 Subject: serial: parisc: GSC: fix build when IOSAPIC is not set commit 6e8793674bb0d1135ca0e5c9f7e16fecbf815926 upstream. There is a build error when using a kernel .config file from 'kernel test robot' for a different build problem: hppa64-linux-ld: drivers/tty/serial/8250/8250_gsc.o: in function `.LC3': (.data.rel.ro+0x18): undefined reference to `iosapic_serial_irq' when: CONFIG_GSC=y CONFIG_SERIO_GSCPS2=y CONFIG_SERIAL_8250_GSC=y CONFIG_PCI is not set and hence PCI_LBA is not set. IOSAPIC depends on PCI_LBA, so IOSAPIC is not set/enabled. Make the use of iosapic_serial_irq() conditional to fix the build error. Signed-off-by: Randy Dunlap Reported-by: kernel test robot Cc: "James E.J. Bottomley" Cc: Helge Deller Cc: linux-parisc@vger.kernel.org Cc: Greg Kroah-Hartman Cc: linux-serial@vger.kernel.org Cc: Jiri Slaby Cc: Johan Hovold Suggested-by: Helge Deller Signed-off-by: Helge Deller Cc: stable@vger.kernel.org Signed-off-by: Helge Deller Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/8250/8250_gsc.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/tty/serial/8250') diff --git a/drivers/tty/serial/8250/8250_gsc.c b/drivers/tty/serial/8250/8250_gsc.c index 673cda3d011d..948d0a1c6ae8 100644 --- a/drivers/tty/serial/8250/8250_gsc.c +++ b/drivers/tty/serial/8250/8250_gsc.c @@ -26,7 +26,7 @@ static int __init serial_init_chip(struct parisc_device *dev) unsigned long address; int err; -#ifdef CONFIG_64BIT +#if defined(CONFIG_64BIT) && defined(CONFIG_IOSAPIC) if (!dev->irq && (dev->id.sversion == 0xad)) dev->irq = iosapic_serial_irq(dev); #endif -- cgit v1.2.3 From d6c4fc0d903fbcc8e1190ed12bfd80f5d031c41f Mon Sep 17 00:00:00 2001 From: Zev Weiss Date: Thu, 10 Feb 2022 16:42:03 -0800 Subject: serial: 8250_aspeed_vuart: add PORT_ASPEED_VUART port type [ Upstream commit a603ca60cebff8589882427a67f870ed946b3fc8 ] Commit 54da3e381c2b ("serial: 8250_aspeed_vuart: use UPF_IOREMAP to set up register mapping") fixed a bug that had, as a side-effect, prevented the 8250_aspeed_vuart driver from enabling the VUART's FIFOs. However, fixing that (and hence enabling the FIFOs) has in turn revealed what appears to be a hardware bug in the ASPEED VUART in which the host-side THRE bit doesn't get if the BMC-side receive FIFO trigger level is set to anything but one byte. This causes problems for polled-mode writes from the host -- for example, Linux kernel console writes proceed at a glacial pace (less than 100 bytes per second) because the write path waits for a 10ms timeout to expire after every character instead of being able to continue on to the next character upon seeing THRE asserted. (GRUB behaves similarly.) As a workaround, introduce a new port type for the ASPEED VUART that's identical to PORT_16550A as it had previously been using, but with UART_FCR_R_TRIG_00 instead to set the receive FIFO trigger level to one byte, which (experimentally) seems to avoid the problematic THRE behavior. Fixes: 54da3e381c2b ("serial: 8250_aspeed_vuart: use UPF_IOREMAP to set up register mapping") Tested-by: Konstantin Aladyshev Reviewed-by: Andy Shevchenko Signed-off-by: Zev Weiss Link: https://lore.kernel.org/r/20220211004203.14915-1-zev@bewilderbeest.net Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin --- drivers/tty/serial/8250/8250_aspeed_vuart.c | 2 +- drivers/tty/serial/8250/8250_port.c | 8 ++++++++ include/uapi/linux/serial_core.h | 3 +++ 3 files changed, 12 insertions(+), 1 deletion(-) (limited to 'drivers/tty/serial/8250') diff --git a/drivers/tty/serial/8250/8250_aspeed_vuart.c b/drivers/tty/serial/8250/8250_aspeed_vuart.c index 2350fb3bb5e4..c2cecc6f47db 100644 --- a/drivers/tty/serial/8250/8250_aspeed_vuart.c +++ b/drivers/tty/serial/8250/8250_aspeed_vuart.c @@ -487,7 +487,7 @@ static int aspeed_vuart_probe(struct platform_device *pdev) port.port.irq = irq_of_parse_and_map(np, 0); port.port.handle_irq = aspeed_vuart_handle_irq; port.port.iotype = UPIO_MEM; - port.port.type = PORT_16550A; + port.port.type = PORT_ASPEED_VUART; port.port.uartclk = clk; port.port.flags = UPF_SHARE_IRQ | UPF_BOOT_AUTOCONF | UPF_IOREMAP | UPF_FIXED_PORT | UPF_FIXED_TYPE | UPF_NO_THRE_TEST; diff --git a/drivers/tty/serial/8250/8250_port.c b/drivers/tty/serial/8250/8250_port.c index ec88b706e882..b470bc747b99 100644 --- a/drivers/tty/serial/8250/8250_port.c +++ b/drivers/tty/serial/8250/8250_port.c @@ -307,6 +307,14 @@ static const struct serial8250_config uart_config[] = { .rxtrig_bytes = {1, 32, 64, 112}, .flags = UART_CAP_FIFO | UART_CAP_SLEEP, }, + [PORT_ASPEED_VUART] = { + .name = "ASPEED VUART", + .fifo_size = 16, + .tx_loadsz = 16, + .fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_00, + .rxtrig_bytes = {1, 4, 8, 14}, + .flags = UART_CAP_FIFO, + }, }; /* Uart divisor latch read */ diff --git a/include/uapi/linux/serial_core.h b/include/uapi/linux/serial_core.h index c4042dcfdc0c..8885e69178bd 100644 --- a/include/uapi/linux/serial_core.h +++ b/include/uapi/linux/serial_core.h @@ -68,6 +68,9 @@ /* NVIDIA Tegra Combined UART */ #define PORT_TEGRA_TCU 41 +/* ASPEED AST2x00 virtual UART */ +#define PORT_ASPEED_VUART 42 + /* Intel EG20 */ #define PORT_PCH_8LINE 44 #define PORT_PCH_2LINE 45 -- cgit v1.2.3 From 3a1131f7d2a86131aae4f0fb27802ae6c46ae26a Mon Sep 17 00:00:00 2001 From: Andy Shevchenko Date: Tue, 15 Feb 2022 12:09:20 +0200 Subject: serial: 8250_mid: Balance reference count for PCI DMA device [ Upstream commit 67ec6dd0b257bd81b4e9fcac89b29da72f6265e5 ] The pci_get_slot() increases its reference count, the caller must decrement the reference count by calling pci_dev_put(). Fixes: 90b9aacf912a ("serial: 8250_pci: add Intel Tangier support") Fixes: f549e94effa1 ("serial: 8250_pci: add Intel Penwell ports") Reported-by: Qing Wang Signed-off-by: Andy Shevchenko Depends-on: d9eda9bab237 ("serial: 8250_pci: Intel MID UART support to its own driver") Link: https://lore.kernel.org/r/20220215100920.41984-1-andriy.shevchenko@linux.intel.com Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin --- drivers/tty/serial/8250/8250_mid.c | 19 +++++++++++++++---- 1 file changed, 15 insertions(+), 4 deletions(-) (limited to 'drivers/tty/serial/8250') diff --git a/drivers/tty/serial/8250/8250_mid.c b/drivers/tty/serial/8250/8250_mid.c index efa0515139f8..e6c1791609dd 100644 --- a/drivers/tty/serial/8250/8250_mid.c +++ b/drivers/tty/serial/8250/8250_mid.c @@ -73,6 +73,11 @@ static int pnw_setup(struct mid8250 *mid, struct uart_port *p) return 0; } +static void pnw_exit(struct mid8250 *mid) +{ + pci_dev_put(mid->dma_dev); +} + static int tng_handle_irq(struct uart_port *p) { struct mid8250 *mid = p->private_data; @@ -124,6 +129,11 @@ static int tng_setup(struct mid8250 *mid, struct uart_port *p) return 0; } +static void tng_exit(struct mid8250 *mid) +{ + pci_dev_put(mid->dma_dev); +} + static int dnv_handle_irq(struct uart_port *p) { struct mid8250 *mid = p->private_data; @@ -330,9 +340,9 @@ static int mid8250_probe(struct pci_dev *pdev, const struct pci_device_id *id) pci_set_drvdata(pdev, mid); return 0; + err: - if (mid->board->exit) - mid->board->exit(mid); + mid->board->exit(mid); return ret; } @@ -342,8 +352,7 @@ static void mid8250_remove(struct pci_dev *pdev) serial8250_unregister_port(mid->line); - if (mid->board->exit) - mid->board->exit(mid); + mid->board->exit(mid); } static const struct mid8250_board pnw_board = { @@ -351,6 +360,7 @@ static const struct mid8250_board pnw_board = { .freq = 50000000, .base_baud = 115200, .setup = pnw_setup, + .exit = pnw_exit, }; static const struct mid8250_board tng_board = { @@ -358,6 +368,7 @@ static const struct mid8250_board tng_board = { .freq = 38400000, .base_baud = 1843200, .setup = tng_setup, + .exit = tng_exit, }; static const struct mid8250_board dnv_board = { -- cgit v1.2.3 From b59173ff16fbfa94223457cc97cce943867a27db Mon Sep 17 00:00:00 2001 From: Andy Shevchenko Date: Wed, 23 Feb 2022 17:12:40 +0200 Subject: serial: 8250_lpss: Balance reference count for PCI DMA device [ Upstream commit 5318f70da7e82649d794fc27d8a127c22aa3566e ] The pci_get_slot() increases its reference count, the caller must decrement the reference count by calling pci_dev_put(). Fixes: 9a1870ce812e ("serial: 8250: don't use slave_id of dma_slave_config") Depends-on: a13e19cf3dc1 ("serial: 8250_lpss: split LPSS driver to separate module") Reported-by: Qing Wang Signed-off-by: Andy Shevchenko Link: https://lore.kernel.org/r/20220223151240.70248-1-andriy.shevchenko@linux.intel.com Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin --- drivers/tty/serial/8250/8250_lpss.c | 28 ++++++++++++++++++++++------ 1 file changed, 22 insertions(+), 6 deletions(-) (limited to 'drivers/tty/serial/8250') diff --git a/drivers/tty/serial/8250/8250_lpss.c b/drivers/tty/serial/8250/8250_lpss.c index 848d81e3838c..49ae73f4d3a0 100644 --- a/drivers/tty/serial/8250/8250_lpss.c +++ b/drivers/tty/serial/8250/8250_lpss.c @@ -121,8 +121,7 @@ static int byt_serial_setup(struct lpss8250 *lpss, struct uart_port *port) { struct dw_dma_slave *param = &lpss->dma_param; struct pci_dev *pdev = to_pci_dev(port->dev); - unsigned int dma_devfn = PCI_DEVFN(PCI_SLOT(pdev->devfn), 0); - struct pci_dev *dma_dev = pci_get_slot(pdev->bus, dma_devfn); + struct pci_dev *dma_dev; switch (pdev->device) { case PCI_DEVICE_ID_INTEL_BYT_UART1: @@ -141,6 +140,8 @@ static int byt_serial_setup(struct lpss8250 *lpss, struct uart_port *port) return -EINVAL; } + dma_dev = pci_get_slot(pdev->bus, PCI_DEVFN(PCI_SLOT(pdev->devfn), 0)); + param->dma_dev = &dma_dev->dev; param->m_master = 0; param->p_master = 1; @@ -156,6 +157,14 @@ static int byt_serial_setup(struct lpss8250 *lpss, struct uart_port *port) return 0; } +static void byt_serial_exit(struct lpss8250 *lpss) +{ + struct dw_dma_slave *param = &lpss->dma_param; + + /* Paired with pci_get_slot() in the byt_serial_setup() above */ + put_device(param->dma_dev); +} + static int ehl_serial_setup(struct lpss8250 *lpss, struct uart_port *port) { struct uart_8250_dma *dma = &lpss->data.dma; @@ -171,6 +180,13 @@ static int ehl_serial_setup(struct lpss8250 *lpss, struct uart_port *port) return 0; } +static void ehl_serial_exit(struct lpss8250 *lpss) +{ + struct uart_8250_port *up = serial8250_get_port(lpss->data.line); + + up->dma = NULL; +} + #ifdef CONFIG_SERIAL_8250_DMA static const struct dw_dma_platform_data qrk_serial_dma_pdata = { .nr_channels = 2, @@ -345,8 +361,7 @@ static int lpss8250_probe(struct pci_dev *pdev, const struct pci_device_id *id) return 0; err_exit: - if (lpss->board->exit) - lpss->board->exit(lpss); + lpss->board->exit(lpss); pci_free_irq_vectors(pdev); return ret; } @@ -357,8 +372,7 @@ static void lpss8250_remove(struct pci_dev *pdev) serial8250_unregister_port(lpss->data.line); - if (lpss->board->exit) - lpss->board->exit(lpss); + lpss->board->exit(lpss); pci_free_irq_vectors(pdev); } @@ -366,12 +380,14 @@ static const struct lpss8250_board byt_board = { .freq = 100000000, .base_baud = 2764800, .setup = byt_serial_setup, + .exit = byt_serial_exit, }; static const struct lpss8250_board ehl_board = { .freq = 200000000, .base_baud = 12500000, .setup = ehl_serial_setup, + .exit = ehl_serial_exit, }; static const struct lpss8250_board qrk_board = { -- cgit v1.2.3 From 3e843460fb4252368bef6c9c8897a40a1268d5a0 Mon Sep 17 00:00:00 2001 From: Uwe Kleine-König Date: Tue, 15 Feb 2022 17:02:36 +0100 Subject: serial: 8250: Fix race condition in RTS-after-send handling MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit [ Upstream commit dedab69fd650ea74710b2e626e63fd35584ef773 ] Set em485->active_timer = NULL isn't always enough to take out the stop timer. While there is a check that it acts in the right state (i.e. waiting for RTS-after-send to pass after sending some chars) but the following might happen: - CPU1: some chars send, shifter becomes empty, stop tx timer armed - CPU0: more chars send before RTS-after-send expired - CPU0: shifter empty irq, port lock taken - CPU1: tx timer triggers, waits for port lock - CPU0: em485->active_timer = &em485->stop_tx_timer, hrtimer_start(), releases lock() - CPU1: get lock, see em485->active_timer == &em485->stop_tx_timer, tear down RTS too early This fix bases on research done by Steffen Trumtrar. Fixes: b86f86e8e7c5 ("serial: 8250: fix potential deadlock in rs485-mode") Signed-off-by: Uwe Kleine-König Link: https://lore.kernel.org/r/20220215160236.344236-1-u.kleine-koenig@pengutronix.de Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin --- drivers/tty/serial/8250/8250_port.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) (limited to 'drivers/tty/serial/8250') diff --git a/drivers/tty/serial/8250/8250_port.c b/drivers/tty/serial/8250/8250_port.c index b470bc747b99..868ccb3e16cf 100644 --- a/drivers/tty/serial/8250/8250_port.c +++ b/drivers/tty/serial/8250/8250_port.c @@ -1623,6 +1623,18 @@ static inline void start_tx_rs485(struct uart_port *port) struct uart_8250_port *up = up_to_u8250p(port); struct uart_8250_em485 *em485 = up->em485; + /* + * While serial8250_em485_handle_stop_tx() is a noop if + * em485->active_timer != &em485->stop_tx_timer, it might happen that + * the timer is still armed and triggers only after the current bunch of + * chars is send and em485->active_timer == &em485->stop_tx_timer again. + * So cancel the timer. There is still a theoretical race condition if + * the timer is already running and only comes around to check for + * em485->active_timer when &em485->stop_tx_timer is armed again. + */ + if (em485->active_timer == &em485->stop_tx_timer) + hrtimer_try_to_cancel(&em485->stop_tx_timer); + em485->active_timer = NULL; if (em485->tx_stopped) { -- cgit v1.2.3 From 16e3238047322c3967e601b2813a10837fb2acb9 Mon Sep 17 00:00:00 2001 From: Ilpo Järvinen Date: Mon, 14 Mar 2022 11:14:32 +0200 Subject: serial: 8250: fix XOFF/XON sending when DMA is used MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit [ Upstream commit f58c252e30cf74f68b0054293adc03b5923b9f0e ] When 8250 UART is using DMA, x_char (XON/XOFF) is never sent to the wire. After this change, x_char is injected correctly. Create uart_xchar_out() helper for sending the x_char out and accounting related to it. It seems that almost every driver does these same steps with x_char. Except for 8250, however, almost all currently lack .serial_out so they cannot immediately take advantage of this new helper. The downside of this patch is that it might reintroduce the problems some devices faced with mixed DMA/non-DMA transfer which caused revert f967fc8f165f (Revert "serial: 8250_dma: don't bother DMA with small transfers"). However, the impact should be limited to cases with XON/XOFF (that didn't work with DMA capable devices to begin with so this problem is not very likely to cause a major issue, if any at all). Fixes: 9ee4b83e51f74 ("serial: 8250: Add support for dmaengine") Reported-by: Gilles Buloz Tested-by: Gilles Buloz Reviewed-by: Andy Shevchenko Signed-off-by: Ilpo Järvinen Link: https://lore.kernel.org/r/20220314091432.4288-2-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin --- drivers/tty/serial/8250/8250_dma.c | 11 ++++++++++- drivers/tty/serial/8250/8250_port.c | 4 +--- drivers/tty/serial/serial_core.c | 14 ++++++++++++++ include/linux/serial_core.h | 2 ++ 4 files changed, 27 insertions(+), 4 deletions(-) (limited to 'drivers/tty/serial/8250') diff --git a/drivers/tty/serial/8250/8250_dma.c b/drivers/tty/serial/8250/8250_dma.c index 890fa7ddaa7f..b3c3f7e5851a 100644 --- a/drivers/tty/serial/8250/8250_dma.c +++ b/drivers/tty/serial/8250/8250_dma.c @@ -64,10 +64,19 @@ int serial8250_tx_dma(struct uart_8250_port *p) struct uart_8250_dma *dma = p->dma; struct circ_buf *xmit = &p->port.state->xmit; struct dma_async_tx_descriptor *desc; + struct uart_port *up = &p->port; int ret; - if (dma->tx_running) + if (dma->tx_running) { + if (up->x_char) { + dmaengine_pause(dma->txchan); + uart_xchar_out(up, UART_TX); + dmaengine_resume(dma->txchan); + } return 0; + } else if (up->x_char) { + uart_xchar_out(up, UART_TX); + } if (uart_tx_stopped(&p->port) || uart_circ_empty(xmit)) { /* We have been called from __dma_tx_complete() */ diff --git a/drivers/tty/serial/8250/8250_port.c b/drivers/tty/serial/8250/8250_port.c index 868ccb3e16cf..723ec0806799 100644 --- a/drivers/tty/serial/8250/8250_port.c +++ b/drivers/tty/serial/8250/8250_port.c @@ -1819,9 +1819,7 @@ void serial8250_tx_chars(struct uart_8250_port *up) int count; if (port->x_char) { - serial_out(up, UART_TX, port->x_char); - port->icount.tx++; - port->x_char = 0; + uart_xchar_out(port, UART_TX); return; } if (uart_tx_stopped(port)) { diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c index dc6129ddef85..eb15423f935a 100644 --- a/drivers/tty/serial/serial_core.c +++ b/drivers/tty/serial/serial_core.c @@ -652,6 +652,20 @@ static void uart_flush_buffer(struct tty_struct *tty) tty_port_tty_wakeup(&state->port); } +/* + * This function performs low-level write of high-priority XON/XOFF + * character and accounting for it. + * + * Requires uart_port to implement .serial_out(). + */ +void uart_xchar_out(struct uart_port *uport, int offset) +{ + serial_port_out(uport, offset, uport->x_char); + uport->icount.tx++; + uport->x_char = 0; +} +EXPORT_SYMBOL_GPL(uart_xchar_out); + /* * This function is used to send a high-priority XON/XOFF character to * the device diff --git a/include/linux/serial_core.h b/include/linux/serial_core.h index c58cc142d23f..8c32935e1059 100644 --- a/include/linux/serial_core.h +++ b/include/linux/serial_core.h @@ -458,6 +458,8 @@ extern void uart_handle_cts_change(struct uart_port *uport, extern void uart_insert_char(struct uart_port *port, unsigned int status, unsigned int overrun, unsigned int ch, unsigned int flag); +void uart_xchar_out(struct uart_port *uport, int offset); + #ifdef CONFIG_MAGIC_SYSRQ_SERIAL #define SYSRQ_TIMEOUT (HZ * 5) -- cgit v1.2.3