From 917e2fd2c53eb3c4162f5397555cbd394390d4bc Mon Sep 17 00:00:00 2001 From: Anton Ivanov Date: Tue, 25 Sep 2018 08:47:13 +0100 Subject: um: Make line/tty semantics use true write IRQ This fixes a long standing bug where large amounts of output could freeze the tty (most commonly seen on stdio console). While the bug has always been there it became more pronounced after moving to the new interrupt controller. The line semantics are now changed to have true IRQ write semantics which should further improve the tty/line subsystem stability and performance Signed-off-by: Anton Ivanov Signed-off-by: Richard Weinberger --- arch/um/drivers/line.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'arch') diff --git a/arch/um/drivers/line.c b/arch/um/drivers/line.c index 8d80b27502e6..7e524efed584 100644 --- a/arch/um/drivers/line.c +++ b/arch/um/drivers/line.c @@ -261,7 +261,7 @@ static irqreturn_t line_write_interrupt(int irq, void *data) if (err == 0) { spin_unlock(&line->lock); return IRQ_NONE; - } else if (err < 0) { + } else if ((err < 0) && (err != -EAGAIN)) { line->head = line->buffer; line->tail = line->buffer; } @@ -284,7 +284,7 @@ int line_setup_irq(int fd, int input, int output, struct line *line, void *data) if (err) return err; if (output) - err = um_request_irq(driver->write_irq, fd, IRQ_NONE, + err = um_request_irq(driver->write_irq, fd, IRQ_WRITE, line_write_interrupt, IRQF_SHARED, driver->write_irq_name, data); return err; -- cgit v1.2.3