From 352fa6ad16b89f8ffd1a93b4419b1a8f2259feab Mon Sep 17 00:00:00 2001 From: Mel Gorman Date: Tue, 2 Mar 2010 22:24:19 +0000 Subject: tty: Take a 256 byte padding into account when buffering below sub-page units The TTY layer takes some care to ensure that only sub-page allocations are made with interrupts disabled. It does this by setting a goal of "TTY_BUFFER_PAGE" to allocate. Unfortunately, while TTY_BUFFER_PAGE takes the size of tty_buffer into account, it fails to account that tty_buffer_find() rounds the buffer size out to the next 256 byte boundary before adding on the size of the tty_buffer. This patch adjusts the TTY_BUFFER_PAGE calculation to take into account the size of the tty_buffer and the padding. Once applied, tty_buffer_alloc() should not require high-order allocations. Signed-off-by: Mel Gorman Cc: stable Signed-off-by: Greg Kroah-Hartman --- include/linux/tty.h | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) (limited to 'include/linux/tty.h') diff --git a/include/linux/tty.h b/include/linux/tty.h index 568369a86306..593228a520e1 100644 --- a/include/linux/tty.h +++ b/include/linux/tty.h @@ -70,12 +70,13 @@ struct tty_buffer { /* * We default to dicing tty buffer allocations to this many characters - * in order to avoid multiple page allocations. We assume tty_buffer itself - * is under 256 bytes. See tty_buffer_find for the allocation logic this - * must match + * in order to avoid multiple page allocations. We know the size of + * tty_buffer itself but it must also be taken into account that the + * the buffer is 256 byte aligned. See tty_buffer_find for the allocation + * logic this must match */ -#define TTY_BUFFER_PAGE ((PAGE_SIZE - 256) / 2) +#define TTY_BUFFER_PAGE (((PAGE_SIZE - sizeof(struct tty_buffer)) / 2) & ~0xFF) struct tty_bufhead { -- cgit v1.2.3 From 336cee42dd52824e360ab419eab4e8888eb054ec Mon Sep 17 00:00:00 2001 From: Jason Wessel Date: Mon, 8 Mar 2010 21:50:11 -0600 Subject: tty_port,usb-console: Fix usb serial console open/close regression Commit e1108a63e10d344284011cccc06328b2cd3e5da3 ("usb_serial: Use the shutdown() operation") breaks the ability to use a usb console starting in 2.6.33. This was observed when using console=ttyUSB0,115200 as a boot argument with an FTDI device. The error is: ftdi_sio ttyUSB0: ftdi_submit_read_urb - failed submitting read urb, error -22 The handling of the ASYNCB_INITIALIZED changed in 2.6.32 such that in tty_port_shutdown() it always clears the flag if it is set. The fix is to add a variable to the tty_port struct to indicate when the tty port is a console. CC: Alan Cox CC: Alan Stern CC: Oliver Neukum CC: Andrew Morton Signed-off-by: Jason Wessel Signed-off-by: Greg Kroah-Hartman --- drivers/char/tty_port.c | 2 +- drivers/usb/serial/console.c | 1 + include/linux/tty.h | 1 + 3 files changed, 3 insertions(+), 1 deletion(-) (limited to 'include/linux/tty.h') diff --git a/drivers/char/tty_port.c b/drivers/char/tty_port.c index be492dd66437..a3bd1d0b66cf 100644 --- a/drivers/char/tty_port.c +++ b/drivers/char/tty_port.c @@ -119,7 +119,7 @@ EXPORT_SYMBOL(tty_port_tty_set); static void tty_port_shutdown(struct tty_port *port) { mutex_lock(&port->mutex); - if (port->ops->shutdown && + if (port->ops->shutdown && !port->console && test_and_clear_bit(ASYNCB_INITIALIZED, &port->flags)) port->ops->shutdown(port); mutex_unlock(&port->mutex); diff --git a/drivers/usb/serial/console.c b/drivers/usb/serial/console.c index b22ac3258523..f347da2ef00a 100644 --- a/drivers/usb/serial/console.c +++ b/drivers/usb/serial/console.c @@ -181,6 +181,7 @@ static int usb_console_setup(struct console *co, char *options) /* The console is special in terms of closing the device so * indicate this port is now acting as a system console. */ port->console = 1; + port->port.console = 1; mutex_unlock(&serial->disc_mutex); return retval; diff --git a/include/linux/tty.h b/include/linux/tty.h index 593228a520e1..4409967db0c4 100644 --- a/include/linux/tty.h +++ b/include/linux/tty.h @@ -224,6 +224,7 @@ struct tty_port { wait_queue_head_t close_wait; /* Close waiters */ wait_queue_head_t delta_msr_wait; /* Modem status change */ unsigned long flags; /* TTY flags ASY_*/ + unsigned char console:1; /* port is a console */ struct mutex mutex; /* Locking */ struct mutex buf_mutex; /* Buffer alloc lock */ unsigned char *xmit_buf; /* Optional buffer */ -- cgit v1.2.3