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- Small fix to virtio_console poll fix from upstream review

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Hans de Goede 2010-09-16 10:53:13 +02:00
parent e34bb01b5f
commit 606af2d7c2
2 changed files with 8 additions and 5 deletions
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3
kernel.spec
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@ -1906,6 +1906,9 @@ fi
# || || # || ||
%changelog %changelog
* Thu Sep 16 2010 Hans de Goede <hdegoede@redhat.com>
- Small fix to virtio_console poll fix from upstream review
* Wed Sep 15 2010 Hans de Goede <hdegoede@redhat.com> * Wed Sep 15 2010 Hans de Goede <hdegoede@redhat.com>
- virtio_console: Fix poll/select blocking even though there is data to read - virtio_console: Fix poll/select blocking even though there is data to read

10
linux-2.6.35.4-virtio_console-fix-poll.patch
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@ -1,4 +1,4 @@
Subject: virtio_console: Fix poll blocking even though there is data to read (version 2) Subject: virtio_console: Fix poll blocking even though there is data to read
From: Hans de Goede <hdegoede@redhat.com> From: Hans de Goede <hdegoede@redhat.com>
I found this while working on a Linux agent for spice, the symptom I was I found this while working on a Linux agent for spice, the symptom I was
@ -10,9 +10,9 @@ read won't block. However if an application reads enough bytes from inbuf
through port_fops_read, to empty the current port->inbuf, port->inbuf through port_fops_read, to empty the current port->inbuf, port->inbuf
will be NULL even though there may be buffers left in the virtqueue. will be NULL even though there may be buffers left in the virtqueue.
This causes poll() to block even though there is data ready to be read, this This causes poll() to block even though there is data to be read, this patch
patch fixes this by using port_has_data(port) instead of the fixes this by using the alredy defined will_read_block utility function
port->inbuf != NULL check. instead of the port->inbuf != NULL check.
Signed-off-By: Hans de Goede <hdegoede@redhat.com> Signed-off-By: Hans de Goede <hdegoede@redhat.com>
diff -up linux-2.6.35.x86_64/drivers/char/virtio_console.c~ linux-2.6.35.x86_64/drivers/char/virtio_console.c diff -up linux-2.6.35.x86_64/drivers/char/virtio_console.c~ linux-2.6.35.x86_64/drivers/char/virtio_console.c
@ -23,7 +23,7 @@ diff -up linux-2.6.35.x86_64/drivers/char/virtio_console.c~ linux-2.6.35.x86_64/
ret = 0; ret = 0;
- if (port->inbuf) - if (port->inbuf)
+ if (port_has_data(port)) + if (!will_read_block(port))
ret |= POLLIN | POLLRDNORM; ret |= POLLIN | POLLRDNORM;
if (!will_write_block(port)) if (!will_write_block(port))
ret |= POLLOUT; ret |= POLLOUT;