From: Aaron Sierra Date: Thu, 1 Aug 2019 18:59:56 +0000 (-0500) Subject: serial: 8250_exar: Absorb remaining 8250_port INT0 support X-Git-Tag: v5.4-rc1~135^2~73 X-Git-Url: https://asedeno.scripts.mit.edu/gitweb/?a=commitdiff_plain;h=72169e4234d4cd3cd177d3021efde82bbdfa43e8;p=linux.git serial: 8250_exar: Absorb remaining 8250_port INT0 support Move INT0 clearing out of common, per-port serial8250_do_startup() into PCI device probe/resume. As described in commit 2c0ac5b48a35 ("serial: exar: Fix stuck MSIs"), the purpose of clearing INT0 is to prevent the PCI interrupt line from becoming stuck asserted, "which is fatal with edge-triggered MSIs". Like the clearing via interrupt handler that moved from common code in commit c7e1b4059075 ("tty: serial: exar: Relocate sleep wake-up handling"), this clearing at startup can be better handled at the PCI device level. Cc: Jan Kiszka Cc: Sudip Mukherjee Signed-off-by: Aaron Sierra Reviewed-by: Andy Shevchenko Link: https://lore.kernel.org/r/20190801185956.3222-1-asierra@xes-inc.com Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/tty/serial/8250/8250_exar.c b/drivers/tty/serial/8250/8250_exar.c index 357e20a6566f..3e93bd2326c9 100644 --- a/drivers/tty/serial/8250/8250_exar.c +++ b/drivers/tty/serial/8250/8250_exar.c @@ -493,6 +493,16 @@ static void pci_xr17v35x_exit(struct pci_dev *pcidev) port->port.private_data = NULL; } +static inline void exar_misc_clear(struct exar8250 *priv) +{ + /* Clear all PCI interrupts by reading INT0. No effect on IIR */ + readb(priv->virt + UART_EXAR_INT0); + + /* Clear INT0 for Expansion Interface slave ports, too */ + if (priv->board->num_ports > 8) + readb(priv->virt + 0x2000 + UART_EXAR_INT0); +} + /* * These Exar UARTs have an extra interrupt indicator that could fire for a * few interrupts that are not presented/cleared through IIR. One of which is @@ -504,14 +514,7 @@ static void pci_xr17v35x_exit(struct pci_dev *pcidev) */ static irqreturn_t exar_misc_handler(int irq, void *data) { - struct exar8250 *priv = data; - - /* Clear all PCI interrupts by reading INT0. No effect on IIR */ - readb(priv->virt + UART_EXAR_INT0); - - /* Clear INT0 for Expansion Interface slave ports, too */ - if (priv->board->num_ports > 8) - readb(priv->virt + 0x2000 + UART_EXAR_INT0); + exar_misc_clear(data); return IRQ_HANDLED; } @@ -584,6 +587,9 @@ exar_pci_probe(struct pci_dev *pcidev, const struct pci_device_id *ent) if (rc) return rc; + /* Clear interrupts */ + exar_misc_clear(priv); + for (i = 0; i < nr_ports && i < maxnr; i++) { rc = board->setup(priv, pcidev, &uart, i); if (rc) { @@ -642,6 +648,8 @@ static int __maybe_unused exar_resume(struct device *dev) struct exar8250 *priv = dev_get_drvdata(dev); unsigned int i; + exar_misc_clear(priv); + for (i = 0; i < priv->nr; i++) if (priv->line[i] >= 0) serial8250_resume_port(priv->line[i]); diff --git a/drivers/tty/serial/8250/8250_port.c b/drivers/tty/serial/8250/8250_port.c index 995a7e8b7839..706645f89132 100644 --- a/drivers/tty/serial/8250/8250_port.c +++ b/drivers/tty/serial/8250/8250_port.c @@ -40,11 +40,6 @@ #include "8250.h" -/* - * These are definitions for the Exar XR17V35X and XR17(C|D)15X - */ -#define UART_EXAR_INT0 0x80 - /* Nuvoton NPCM timeout register */ #define UART_NPCM_TOR 7 #define UART_NPCM_TOIE BIT(7) /* Timeout Interrupt Enable */ @@ -2138,8 +2133,6 @@ int serial8250_do_startup(struct uart_port *port) serial_port_in(port, UART_RX); serial_port_in(port, UART_IIR); serial_port_in(port, UART_MSR); - if ((port->type == PORT_XR17V35X) || (port->type == PORT_XR17D15X)) - serial_port_in(port, UART_EXAR_INT0); /* * At this point, there's no way the LSR could still be 0xff; @@ -2297,8 +2290,6 @@ int serial8250_do_startup(struct uart_port *port) serial_port_in(port, UART_RX); serial_port_in(port, UART_IIR); serial_port_in(port, UART_MSR); - if ((port->type == PORT_XR17V35X) || (port->type == PORT_XR17D15X)) - serial_port_in(port, UART_EXAR_INT0); up->lsr_saved_flags = 0; up->msr_saved_flags = 0;