drm: zynqmp_dp: Use scope-based mutex helpers

Convert most mutex_(un)lock calls to use (scoped_)guard instead. This
generally reduces line count and prevents bugs like forgetting to unlock
the mutex. I've left traditional calls in a few places where scoped
helpers would be more verbose. This mostly happens where
debugfs_file_put needs to be called regardless. I looked into defining a
CLASS for debugfs_file, but it seems like more effort than it's worth
since debugfs_file_get can fail.

Signed-off-by: Sean Anderson <sean.anderson@linux.dev>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20250207162528.1651426-3-sean.anderson@linux.dev

diff --git a/drivers/gpu/drm/xlnx/zynqmp_dp.c b/drivers/gpu/drm/xlnx/zynqmp_dp.c
index 189a08cdc73c05564f14e0ea41fc999562be192d..63842f657836125518b9eae69c03f2a41fa439aa 100644 (file)
--- a/drivers/gpu/drm/xlnx/zynqmp_dp.c
+++ b/drivers/gpu/drm/xlnx/zynqmp_dp.c
@@ -1534,10 +1534,10 @@ zynqmp_dp_bridge_mode_valid(struct drm_bridge *bridge,
        }
 
        /* Check with link rate and lane count */
-       mutex_lock(&dp->lock);
-       rate = zynqmp_dp_max_rate(dp->link_config.max_rate,
-                                 dp->link_config.max_lanes, dp->config.bpp);
-       mutex_unlock(&dp->lock);
+       scoped_guard(mutex, &dp->lock)
+               rate = zynqmp_dp_max_rate(dp->link_config.max_rate,
+                                         dp->link_config.max_lanes,
+                                         dp->config.bpp);
        if (mode->clock > rate) {
                dev_dbg(dp->dev, "filtered mode %s for high pixel rate\n",
                        mode->name);
@@ -1722,13 +1722,9 @@ disconnected:
 static enum drm_connector_status zynqmp_dp_bridge_detect(struct drm_bridge *bridge)
 {
        struct zynqmp_dp *dp = bridge_to_dp(bridge);
-       enum drm_connector_status ret;
-
-       mutex_lock(&dp->lock);
-       ret = __zynqmp_dp_bridge_detect(dp);
-       mutex_unlock(&dp->lock);
 
-       return ret;
+       guard(mutex)(&dp->lock);
+       return __zynqmp_dp_bridge_detect(dp);
 }
 
 static const struct drm_edid *zynqmp_dp_bridge_edid_read(struct drm_bridge *bridge,
@@ -1881,10 +1877,9 @@ static ssize_t zynqmp_dp_pattern_read(struct file *file, char __user *user_buf,
        if (unlikely(ret))
                return ret;
 
-       mutex_lock(&dp->lock);
-       ret = snprintf(buf, sizeof(buf), "%s\n",
-                      test_pattern_str[dp->test.pattern]);
-       mutex_unlock(&dp->lock);
+       scoped_guard(mutex, &dp->lock)
+               ret = snprintf(buf, sizeof(buf), "%s\n",
+                              test_pattern_str[dp->test.pattern]);
 
        debugfs_file_put(dentry);
        return simple_read_from_buffer(user_buf, count, ppos, buf, ret);
@@ -1939,24 +1934,18 @@ static int zynqmp_dp_enhanced_get(void *data, u64 *val)
 {
        struct zynqmp_dp *dp = data;
 
-       mutex_lock(&dp->lock);
+       guard(mutex)(&dp->lock);
        *val = dp->test.enhanced;
-       mutex_unlock(&dp->lock);
        return 0;
 }
 
 static int zynqmp_dp_enhanced_set(void *data, u64 val)
 {
        struct zynqmp_dp *dp = data;
-       int ret = 0;
 
-       mutex_lock(&dp->lock);
+       guard(mutex)(&dp->lock);
        dp->test.enhanced = val;
-       if (dp->test.active)
-               ret = zynqmp_dp_test_setup(dp);
-       mutex_unlock(&dp->lock);
-
-       return ret;
+       return dp->test.active ? zynqmp_dp_test_setup(dp) : 0;
 }
 
 DEFINE_DEBUGFS_ATTRIBUTE(fops_zynqmp_dp_enhanced, zynqmp_dp_enhanced_get,
@@ -1966,24 +1955,19 @@ static int zynqmp_dp_downspread_get(void *data, u64 *val)
 {
        struct zynqmp_dp *dp = data;
 
-       mutex_lock(&dp->lock);
+       guard(mutex)(&dp->lock);
        *val = dp->test.downspread;
-       mutex_unlock(&dp->lock);
        return 0;
 }
 
 static int zynqmp_dp_downspread_set(void *data, u64 val)
 {
        struct zynqmp_dp *dp = data;
-       int ret = 0;
 
-       mutex_lock(&dp->lock);
+       guard(mutex)(&dp->lock);
        dp->test.downspread = val;
-       if (dp->test.active)
-               ret = zynqmp_dp_test_setup(dp);
-       mutex_unlock(&dp->lock);
 
-       return ret;
+       return dp->test.active ? zynqmp_dp_test_setup(dp) : 0;
 }
 
 DEFINE_DEBUGFS_ATTRIBUTE(fops_zynqmp_dp_downspread, zynqmp_dp_downspread_get,
@@ -1993,33 +1977,32 @@ static int zynqmp_dp_active_get(void *data, u64 *val)
 {
        struct zynqmp_dp *dp = data;
 
-       mutex_lock(&dp->lock);
+       guard(mutex)(&dp->lock);
        *val = dp->test.active;
-       mutex_unlock(&dp->lock);
        return 0;
 }
 
 static int zynqmp_dp_active_set(void *data, u64 val)
 {
        struct zynqmp_dp *dp = data;
-       int ret = 0;
+       int ret;
 
-       mutex_lock(&dp->lock);
+       guard(mutex)(&dp->lock);
        if (val) {
                if (val < 2) {
                        ret = zynqmp_dp_test_setup(dp);
                        if (ret)
-                               goto out;
+                               return ret;
                }
 
                ret = zynqmp_dp_set_test_pattern(dp, dp->test.pattern,
                                                 dp->test.custom);
                if (ret)
-                       goto out;
+                       return ret;
 
                ret = zynqmp_dp_update_vs_emph(dp, dp->test.train_set);
                if (ret)
-                       goto out;
+                       return ret;
 
                dp->test.active = true;
        } else {
@@ -2032,10 +2015,8 @@ static int zynqmp_dp_active_set(void *data, u64 val)
                                 err);
                zynqmp_dp_train_loop(dp);
        }
-out:
-       mutex_unlock(&dp->lock);
 
-       return ret;
+       return 0;
 }
 
 DEFINE_DEBUGFS_ATTRIBUTE(fops_zynqmp_dp_active, zynqmp_dp_active_get,
@@ -2102,9 +2083,8 @@ static int zynqmp_dp_swing_get(void *data, u64 *val)
        struct zynqmp_dp_train_set_priv *priv = data;
        struct zynqmp_dp *dp = priv->dp;
 
-       mutex_lock(&dp->lock);
+       guard(mutex)(&dp->lock);
        *val = dp->test.train_set[priv->lane] & DP_TRAIN_VOLTAGE_SWING_MASK;
-       mutex_unlock(&dp->lock);
        return 0;
 }
 
@@ -2113,12 +2093,11 @@ static int zynqmp_dp_swing_set(void *data, u64 val)
        struct zynqmp_dp_train_set_priv *priv = data;
        struct zynqmp_dp *dp = priv->dp;
        u8 *train_set = &dp->test.train_set[priv->lane];
-       int ret = 0;
 
        if (val > 3)
                return -EINVAL;
 
-       mutex_lock(&dp->lock);
+       guard(mutex)(&dp->lock);
        *train_set &= ~(DP_TRAIN_MAX_SWING_REACHED |
                        DP_TRAIN_VOLTAGE_SWING_MASK);
        *train_set |= val;
@@ -2126,10 +2105,9 @@ static int zynqmp_dp_swing_set(void *data, u64 val)
                *train_set |= DP_TRAIN_MAX_SWING_REACHED;
 
        if (dp->test.active)
-               ret = zynqmp_dp_update_vs_emph(dp, dp->test.train_set);
-       mutex_unlock(&dp->lock);
+               return zynqmp_dp_update_vs_emph(dp, dp->test.train_set);
 
-       return ret;
+       return 0;
 }
 
 DEFINE_DEBUGFS_ATTRIBUTE(fops_zynqmp_dp_swing, zynqmp_dp_swing_get,
@@ -2140,10 +2118,9 @@ static int zynqmp_dp_preemphasis_get(void *data, u64 *val)
        struct zynqmp_dp_train_set_priv *priv = data;
        struct zynqmp_dp *dp = priv->dp;
 
-       mutex_lock(&dp->lock);
+       guard(mutex)(&dp->lock);
        *val = FIELD_GET(DP_TRAIN_PRE_EMPHASIS_MASK,
                         dp->test.train_set[priv->lane]);
-       mutex_unlock(&dp->lock);
        return 0;
 }
 
@@ -2152,12 +2129,11 @@ static int zynqmp_dp_preemphasis_set(void *data, u64 val)
        struct zynqmp_dp_train_set_priv *priv = data;
        struct zynqmp_dp *dp = priv->dp;
        u8 *train_set = &dp->test.train_set[priv->lane];
-       int ret = 0;
 
        if (val > 2)
                return -EINVAL;
 
-       mutex_lock(&dp->lock);
+       guard(mutex)(&dp->lock);
        *train_set &= ~(DP_TRAIN_MAX_PRE_EMPHASIS_REACHED |
                        DP_TRAIN_PRE_EMPHASIS_MASK);
        *train_set |= val;
@@ -2165,10 +2141,9 @@ static int zynqmp_dp_preemphasis_set(void *data, u64 val)
                *train_set |= DP_TRAIN_MAX_PRE_EMPHASIS_REACHED;
 
        if (dp->test.active)
-               ret = zynqmp_dp_update_vs_emph(dp, dp->test.train_set);
-       mutex_unlock(&dp->lock);
+               return zynqmp_dp_update_vs_emph(dp, dp->test.train_set);
 
-       return ret;
+       return 0;
 }
 
 DEFINE_DEBUGFS_ATTRIBUTE(fops_zynqmp_dp_preemphasis, zynqmp_dp_preemphasis_get,
@@ -2178,31 +2153,24 @@ static int zynqmp_dp_lanes_get(void *data, u64 *val)
 {
        struct zynqmp_dp *dp = data;
 
-       mutex_lock(&dp->lock);
+       guard(mutex)(&dp->lock);
        *val = dp->test.link_cnt;
-       mutex_unlock(&dp->lock);
        return 0;
 }
 
 static int zynqmp_dp_lanes_set(void *data, u64 val)
 {
        struct zynqmp_dp *dp = data;
-       int ret = 0;
 
        if (val > ZYNQMP_DP_MAX_LANES)
                return -EINVAL;
 
-       mutex_lock(&dp->lock);
-       if (val > dp->num_lanes) {
-               ret = -EINVAL;
-       } else {
-               dp->test.link_cnt = val;
-               if (dp->test.active)
-                       ret = zynqmp_dp_test_setup(dp);
-       }
-       mutex_unlock(&dp->lock);
+       guard(mutex)(&dp->lock);
+       if (val > dp->num_lanes)
+               return -EINVAL;
 
-       return ret;
+       dp->test.link_cnt = val;
+       return dp->test.active ? zynqmp_dp_test_setup(dp) : 0;
 }
 
 DEFINE_DEBUGFS_ATTRIBUTE(fops_zynqmp_dp_lanes, zynqmp_dp_lanes_get,
@@ -2212,9 +2180,8 @@ static int zynqmp_dp_rate_get(void *data, u64 *val)
 {
        struct zynqmp_dp *dp = data;
 
-       mutex_lock(&dp->lock);
+       guard(mutex)(&dp->lock);
        *val = drm_dp_bw_code_to_link_rate(dp->test.bw_code) * 10000ULL;
-       mutex_unlock(&dp->lock);
        return 0;
 }
 
@@ -2222,7 +2189,6 @@ static int zynqmp_dp_rate_set(void *data, u64 val)
 {
        struct zynqmp_dp *dp = data;
        int link_rate;
-       int ret = 0;
        u8 bw_code;
 
        if (do_div(val, 10000))
@@ -2237,13 +2203,9 @@ static int zynqmp_dp_rate_set(void *data, u64 val)
            bw_code != DP_LINK_BW_5_4)
                return -EINVAL;
 
-       mutex_lock(&dp->lock);
+       guard(mutex)(&dp->lock);
        dp->test.bw_code = bw_code;
-       if (dp->test.active)
-               ret = zynqmp_dp_test_setup(dp);
-       mutex_unlock(&dp->lock);
-
-       return ret;
+       return dp->test.active ? zynqmp_dp_test_setup(dp) : 0;
 }
 
 DEFINE_DEBUGFS_ATTRIBUTE(fops_zynqmp_dp_rate, zynqmp_dp_rate_get,
@@ -2253,9 +2215,8 @@ static int zynqmp_dp_ignore_aux_errors_get(void *data, u64 *val)
 {
        struct zynqmp_dp *dp = data;
 
-       mutex_lock(&dp->aux.hw_mutex);
+       guard(mutex)(&dp->lock);
        *val = dp->ignore_aux_errors;
-       mutex_unlock(&dp->aux.hw_mutex);
        return 0;
 }
 
@@ -2266,9 +2227,8 @@ static int zynqmp_dp_ignore_aux_errors_set(void *data, u64 val)
        if (val != !!val)
                return -EINVAL;
 
-       mutex_lock(&dp->aux.hw_mutex);
+       guard(mutex)(&dp->lock);
        dp->ignore_aux_errors = val;
-       mutex_unlock(&dp->aux.hw_mutex);
        return 0;
 }
 
@@ -2280,9 +2240,8 @@ static int zynqmp_dp_ignore_hpd_get(void *data, u64 *val)
 {
        struct zynqmp_dp *dp = data;
 
-       mutex_lock(&dp->lock);
+       guard(mutex)(&dp->lock);
        *val = dp->ignore_hpd;
-       mutex_unlock(&dp->lock);
        return 0;
 }
 
@@ -2293,9 +2252,8 @@ static int zynqmp_dp_ignore_hpd_set(void *data, u64 val)
        if (val != !!val)
                return -EINVAL;
 
-       mutex_lock(&dp->lock);
+       guard(mutex)(&dp->lock);
        dp->ignore_hpd = val;
-       mutex_unlock(&dp->lock);
        return 0;
 }
 
@@ -2391,14 +2349,12 @@ static void zynqmp_dp_hpd_work_func(struct work_struct *work)
        struct zynqmp_dp *dp = container_of(work, struct zynqmp_dp, hpd_work);
        enum drm_connector_status status;
 
-       mutex_lock(&dp->lock);
-       if (dp->ignore_hpd) {
-               mutex_unlock(&dp->lock);
-               return;
-       }
+       scoped_guard(mutex, &dp->lock) {
+               if (dp->ignore_hpd)
+                       return;
 
-       status = __zynqmp_dp_bridge_detect(dp);
-       mutex_unlock(&dp->lock);
+               status = __zynqmp_dp_bridge_detect(dp);
+       }
 
        drm_bridge_hpd_notify(&dp->bridge, status);
 }
@@ -2410,11 +2366,9 @@ static void zynqmp_dp_hpd_irq_work_func(struct work_struct *work)
        u8 status[DP_LINK_STATUS_SIZE + 2];
        int err;
 
-       mutex_lock(&dp->lock);
-       if (dp->ignore_hpd) {
-               mutex_unlock(&dp->lock);
+       guard(mutex)(&dp->lock);
+       if (dp->ignore_hpd)
                return;
-       }
 
        err = drm_dp_dpcd_read(&dp->aux, DP_SINK_COUNT, status,
                               DP_LINK_STATUS_SIZE + 2);
@@ -2428,7 +2382,6 @@ static void zynqmp_dp_hpd_irq_work_func(struct work_struct *work)
                        zynqmp_dp_train_loop(dp);
                }
        }
-       mutex_unlock(&dp->lock);
 }
 
 static irqreturn_t zynqmp_dp_irq_handler(int irq, void *data)