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From: Amit Shah <amit.shah@redhat.com>
To: Virtualization List <virtualization@lists.linux-foundation.org>
Cc: Amit Shah <amit.shah@redhat.com>,
	Juan Quintela <quintela@redhat.com>,
	"Michael S. Tsirkin" <mst@redhat.com>
Subject: [PATCH 05/11] virtio: console: Don't call hvc_remove() on unplugging console ports
Date: Thu,  8 Apr 2010 20:19:34 +0530	[thread overview]
Message-ID: <1270738180-21170-6-git-send-email-amit.shah@redhat.com> (raw)
In-Reply-To: <1270738180-21170-5-git-send-email-amit.shah@redhat.com>

hvc_remove() has some bug which freezes other active hvc ports when one
port is removed.

So disable calling of hvc_remove() which deregisters a port with the
hvc_console.

If the hvc_console code calls into our get_chars() routine as a result
of a poll operation, we will return -EPIPE and the hvc_console code will
then do the necessary cleanup.

This call will be restored when the bug in hvc_remove() is found and
fixed.

Signed-off-by: Amit Shah <amit.shah@redhat.com>
---
 drivers/char/virtio_console.c |   11 +++++++++++
 1 files changed, 11 insertions(+), 0 deletions(-)

diff --git a/drivers/char/virtio_console.c b/drivers/char/virtio_console.c
index 24fa759..6adde65 100644
--- a/drivers/char/virtio_console.c
+++ b/drivers/char/virtio_console.c
@@ -869,7 +869,18 @@ static int remove_port(struct port *port)
 		spin_lock_irq(&pdrvdata_lock);
 		list_del(&port->cons.list);
 		spin_unlock_irq(&pdrvdata_lock);
+#if 0
+		/*
+		 * hvc_remove() not called as removing one hvc port
+		 * results in other hvc ports getting frozen.
+		 *
+		 * Once this is resolved in hvc, this functionality
+		 * will be enabled.  Till that is done, the -EPIPE
+		 * return from get_chars() above will help
+		 * hvc_console.c to clean up on ports we remove here.
+		 */
 		hvc_remove(port->cons.hvc);
+#endif
 	}
 	if (port->guest_connected)
 		send_control_msg(port, VIRTIO_CONSOLE_PORT_OPEN, 0);
-- 
1.6.2.5

  reply	other threads:[~2010-04-08 14:49 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-04-08 14:49 [PATCH 00/11] (v6) virtio: console: Fixes, new way of discovering ports Amit Shah
2010-04-08 14:49 ` [PATCH 01/11] Revert "virtio: disable multiport console support." Amit Shah
2010-04-08 14:49   ` [PATCH 02/11] virtio: console: Add a __send_control_msg() that can send messages without a valid port Amit Shah
2010-04-08 14:49     ` [PATCH 03/11] virtio: console: Let host know of port or device add failures Amit Shah
2010-04-08 14:49       ` [PATCH 04/11] virtio: console: Return -EPIPE to hvc_console if we lost the connection Amit Shah
2010-04-08 14:49         ` Amit Shah [this message]
2010-04-08 14:49           ` [PATCH 06/11] virtio: console: Remove config work handler Amit Shah
2010-04-08 14:49             ` [PATCH 07/11] virtio: console: Move code around for future patches Amit Shah
2010-04-08 14:49               ` [PATCH 08/11] virtio: console: Use a control message to add ports Amit Shah
2010-04-08 14:49                 ` [PATCH 09/11] virtio: console: Don't always create a port 0 if using multiport Amit Shah
2010-04-08 14:49                   ` [PATCH 10/11] virtio: console: Rename wait_is_over() to will_read_block() Amit Shah
2010-04-08 14:49                     ` [PATCH 11/11] virtio: console: Add support for nonblocking write()s Amit Shah
2010-04-10  7:19                   ` [PATCH 09/11] virtio: console: Don't always create a port 0 if using multiport Amit Shah

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