drm/i915: Don't read dpcd for disconnected ports

Reading from disconnected ports will spit out timeout error
on the dmesg. Skip the attempted read if the port is not
connected and avoid confusing users/testcases about
expected timeouts.

This new dpcd debugfs entry was introduced by commit aa7471d228eb
("drm/i915: add i915 specific connector debugfs file for DPCD")

v2 by Jani: move the check at the top, out of the loop.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=90060
Tested-by: yex.tian@intel.com
Cc: Jani Nikula <jani.nikula@intel.com>
Cc: Bob Paauwe <bob.j.paauwe@intel.com>
Signed-off-by: Mika Kuoppala <mika.kuoppala@intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c
index adbbddab42c65278d78ff83ca6b6347ade7cc6b0..a32b669bab89b6d9469297081102bb273b19c477 100644 (file)
--- a/drivers/gpu/drm/i915/i915_debugfs.c
+++ b/drivers/gpu/drm/i915/i915_debugfs.c
@@ -5154,6 +5154,9 @@ static int i915_dpcd_show(struct seq_file *m, void *data)
        ssize_t err;
        int i;
 
+       if (connector->status != connector_status_connected)
+               return -ENODEV;
+
        for (i = 0; i < ARRAY_SIZE(i915_dpcd_debug); i++) {
                const struct dpcd_block *b = &i915_dpcd_debug[i];
                size_t size = b->end ? b->end - b->offset + 1 : (b->size ?: 1);