doubletalk: probe failure causes OOPS

The code bothers to probe for the device, but on failing to find it proceeds
to try and release a NULL resource, thereby ruining it's prior good
behaviour

Resolves-Bug: https://bugzilla.kernel.org/show_bug.cgi?id=88581
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

1 files changed, 4 insertions, 3 deletions

diff --git a/drivers/staging/speakup/speakup_dtlk.c b/drivers/staging/speakup/speakup_dtlk.c
index d7d515273896..ffd85e1a885b 100644
--- a/drivers/staging/speakup/speakup_dtlk.c
+++ b/drivers/staging/speakup/speakup_dtlk.c
@@ -325,7 +325,7 @@ static struct synth_settings *synth_interrogate(struct spk_synth *synth)
 
 static int synth_probe(struct spk_synth *synth)
 {
-                unsigned int port_val = 0;
+        unsigned int port_val = 0;
         int i = 0;
         struct synth_settings *sp;
 
@@ -361,7 +361,8 @@ static int synth_probe(struct spk_synth *synth)
         port_val &= 0xfbff;
         if (port_val != 0x107f) {
                 pr_info("DoubleTalk PC: not found\n");
-                synth_release_region(synth_lpc, SYNTH_IO_EXTENT);
+                if (synth_lpc)
+                        synth_release_region(synth_lpc, SYNTH_IO_EXTENT);
                 return -ENODEV;
         }
         while (inw_p(synth_lpc) != 0x147f)
@@ -369,7 +370,7 @@ static int synth_probe(struct spk_synth *synth)
         sp = synth_interrogate(synth);
         pr_info("%s: %03x-%03x, ROM ver %s, s/n %u, driver: %s\n",
                 synth->long_name, synth_lpc, synth_lpc+SYNTH_IO_EXTENT - 1,
-         sp->rom_version, sp->serial_number, synth->version);
+                sp->rom_version, sp->serial_number, synth->version);
         synth->alive = 1;
         return 0;
 }