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| author | Nicholas Piggin <npiggin@gmail.com> | 2018-09-09 15:39:16 +1000 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-09-10 18:04:31 +0200 |
| commit | 7f2bf7840b74a160f908db83bc8829f8de10629b (patch) | |
| tree | 2a34c7484d8288d850e3343244f46a570bf851ce /drivers | |
| parent | 68b2fc714fb1e08385f9c810d84f06affd007350 (diff) | |
| download | linux-7f2bf7840b74a160f908db83bc8829f8de10629b.tar.gz linux-7f2bf7840b74a160f908db83bc8829f8de10629b.tar.bz2 linux-7f2bf7840b74a160f908db83bc8829f8de10629b.zip | |
tty: hvc: hvc_write() fix break condition
Commit 550ddadcc758 ("tty: hvc: hvc_write() may sleep") broke the
termination condition in case the driver stops accepting characters.
This can result in unnecessary polling of the busy driver.
Restore it by testing the hvc_push return code.
Tested-by: Matteo Croce <mcroce@redhat.com>
Tested-by: Jason Gunthorpe <jgg@mellanox.com>
Tested-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/tty/hvc/hvc_console.c | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/drivers/tty/hvc/hvc_console.c b/drivers/tty/hvc/hvc_console.c index bacf9b73ec98..27284a2dcd2b 100644 --- a/drivers/tty/hvc/hvc_console.c +++ b/drivers/tty/hvc/hvc_console.c @@ -522,6 +522,8 @@ static int hvc_write(struct tty_struct *tty, const unsigned char *buf, int count return -EIO; while (count > 0) { + int ret = 0; + spin_lock_irqsave(&hp->lock, flags); rsize = hp->outbuf_size - hp->n_outbuf; @@ -537,10 +539,13 @@ static int hvc_write(struct tty_struct *tty, const unsigned char *buf, int count } if (hp->n_outbuf > 0) - hvc_push(hp); + ret = hvc_push(hp); spin_unlock_irqrestore(&hp->lock, flags); + if (!ret) + break; + if (count) { if (hp->n_outbuf > 0) hvc_flush(hp); |