drm/i915/tc: Fix -Wformat-truncation in intel_tc_port_init

[ Upstream commit 9506fba463fcbdf8c8b7af3ec9ee34360df843fe ]

Fix below compiler warning:

intel_tc.c:1879:11: error: ‘%d’ directive output may be truncated
writing between 1 and 11 bytes into a region of size 3
[-Werror=format-truncation=]
"%c/TC#%d", port_name(port), tc_port + 1);
           ^~
intel_tc.c:1878:2: note: ‘snprintf’ output between 7 and 17 bytes
into a destination of size 8
  snprintf(tc->port_name, sizeof(tc->port_name),
  ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    "%c/TC#%d", port_name(port), tc_port + 1);
    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

v2: use kasprintf(Imre)
v3: use const for port_name, and fix tc mem leak(Imre)

Fixes: 3eafcddf766b ("drm/i915/tc: Move TC port fields to a new intel_tc_port struct")
Cc: Mika Kahola <mika.kahola@intel.com>
Cc: Imre Deak <imre.deak@intel.com>
Cc: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Nirmoy Das <nirmoy.das@intel.com>
Reviewed-by: Andrzej Hajda <andrzej.hajda@intel.com>
Reviewed-by: Imre Deak <imre.deak@intel.com>
Reviewed-by: Mika Kahola <mika.kahola@intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231026125636.5080-1-nirmoy.das@intel.com
(cherry picked from commit 70a3cbbe620ee66afb0c066624196077767e61b2)
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/gpu/drm/i915/display/intel_tc.c b/drivers/gpu/drm/i915/display/intel_tc.c
index 3ebf418..cdf2455 100644 (file)
--- a/drivers/gpu/drm/i915/display/intel_tc.c
+++ b/drivers/gpu/drm/i915/display/intel_tc.c
@@ -58,7 +58,7 @@ struct intel_tc_port {
        struct delayed_work link_reset_work;
        int link_refcount;
        bool legacy_port:1;
-       char port_name[8];
+       const char *port_name;
        enum tc_port_mode mode;
        enum tc_port_mode init_mode;
        enum phy_fia phy_fia;
@@ -1841,8 +1841,12 @@ int intel_tc_port_init(struct intel_digital_port *dig_port, bool is_legacy)
        else
                tc->phy_ops = &icl_tc_phy_ops;
 
-       snprintf(tc->port_name, sizeof(tc->port_name),
-                "%c/TC#%d", port_name(port), tc_port + 1);
+       tc->port_name = kasprintf(GFP_KERNEL, "%c/TC#%d", port_name(port),
+                                 tc_port + 1);
+       if (!tc->port_name) {
+               kfree(tc);
+               return -ENOMEM;
+       }
 
        mutex_init(&tc->lock);
        /* TODO: Combine the two works */
@@ -1863,6 +1867,7 @@ void intel_tc_port_cleanup(struct intel_digital_port *dig_port)
 {
        intel_tc_port_suspend(dig_port);
 
+       kfree(dig_port->tc->port_name);
        kfree(dig_port->tc);
        dig_port->tc = NULL;
 }