drm/xe/pcode: Initialize data0 for pcode read routine

There are two registers filled in when reading data from
pcode besides the mailbox itself. Currently, we allow a NULL
value for the second of these two (data1) and assume the first
is defined. However, many of the routines that are calling
this function assume that pcode will ignore the value being
passed in and so leave that first value (data0) defined but
uninitialized. To be safe, make sure this value is always
initialized to something (0 generally) in the event pcode
behavior changes and starts using this value.

v2: Fix sob/author

Signed-off-by: Stuart Summers <stuart.summers@intel.com>
Reviewed-by: Jonathan Cavitt <jonathan.cavitt@intel.com>
Link: https://lore.kernel.org/r/20250819201054.393220-1-stuart.summers@intel.com
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>

diff --git a/drivers/gpu/drm/xe/xe_device_sysfs.c b/drivers/gpu/drm/xe/xe_device_sysfs.c
index bd90157..6ee4225 100644 (file)
--- a/drivers/gpu/drm/xe/xe_device_sysfs.c
+++ b/drivers/gpu/drm/xe/xe_device_sysfs.c
@@ -76,7 +76,7 @@ lb_fan_control_version_show(struct device *dev, struct device_attribute *attr, c
 {
        struct xe_device *xe = pdev_to_xe_device(to_pci_dev(dev));
        struct xe_tile *root = xe_device_get_root_tile(xe);
-       u32 cap, ver_low = FAN_TABLE, ver_high = FAN_TABLE;
+       u32 cap = 0, ver_low = FAN_TABLE, ver_high = FAN_TABLE;
        u16 major = 0, minor = 0, hotfix = 0, build = 0;
        int ret;
 
@@ -115,7 +115,7 @@ lb_voltage_regulator_version_show(struct device *dev, struct device_attribute *a
 {
        struct xe_device *xe = pdev_to_xe_device(to_pci_dev(dev));
        struct xe_tile *root = xe_device_get_root_tile(xe);
-       u32 cap, ver_low = VR_CONFIG, ver_high = VR_CONFIG;
+       u32 cap = 0, ver_low = VR_CONFIG, ver_high = VR_CONFIG;
        u16 major = 0, minor = 0, hotfix = 0, build = 0;
        int ret;
 
@@ -153,7 +153,7 @@ static int late_bind_create_files(struct device *dev)
 {
        struct xe_device *xe = pdev_to_xe_device(to_pci_dev(dev));
        struct xe_tile *root = xe_device_get_root_tile(xe);
-       u32 cap;
+       u32 cap = 0;
        int ret;
 
        xe_pm_runtime_get(xe);
@@ -186,7 +186,7 @@ static void late_bind_remove_files(struct device *dev)
 {
        struct xe_device *xe = pdev_to_xe_device(to_pci_dev(dev));
        struct xe_tile *root = xe_device_get_root_tile(xe);
-       u32 cap;
+       u32 cap = 0;
        int ret;
 
        xe_pm_runtime_get(xe);

diff --git a/drivers/gpu/drm/xe/xe_hwmon.c b/drivers/gpu/drm/xe/xe_hwmon.c
index c17ed1a..32a76ae 100644 (file)
--- a/drivers/gpu/drm/xe/xe_hwmon.c
+++ b/drivers/gpu/drm/xe/xe_hwmon.c
@@ -179,7 +179,7 @@ static int xe_hwmon_pcode_rmw_power_limit(const struct xe_hwmon *hwmon, u32 attr
                                          u32 clr, u32 set)
 {
        struct xe_tile *root_tile = xe_device_get_root_tile(hwmon->xe);
-       u32 val0, val1;
+       u32 val0 = 0, val1 = 0;
        int ret = 0;
 
        ret = xe_pcode_read(root_tile, PCODE_MBOX(PCODE_POWER_SETUP,
@@ -734,7 +734,7 @@ static int xe_hwmon_power_curr_crit_read(struct xe_hwmon *hwmon, int channel,
                                         long *value, u32 scale_factor)
 {
        int ret;
-       u32 uval;
+       u32 uval = 0;
 
        mutex_lock(&hwmon->hwmon_lock);
 
@@ -918,7 +918,7 @@ xe_hwmon_power_write(struct xe_hwmon *hwmon, u32 attr, int channel, long val)
 static umode_t
 xe_hwmon_curr_is_visible(const struct xe_hwmon *hwmon, u32 attr, int channel)
 {
-       u32 uval;
+       u32 uval = 0;
 
        /* hwmon sysfs attribute of current available only for package */
        if (channel != CHANNEL_PKG)
@@ -1020,7 +1020,7 @@ xe_hwmon_energy_read(struct xe_hwmon *hwmon, u32 attr, int channel, long *val)
 static umode_t
 xe_hwmon_fan_is_visible(struct xe_hwmon *hwmon, u32 attr, int channel)
 {
-       u32 uval;
+       u32 uval = 0;
 
        if (!hwmon->xe->info.has_fan_control)
                return 0;

diff --git a/drivers/gpu/drm/xe/xe_vram_freq.c b/drivers/gpu/drm/xe/xe_vram_freq.c
index b26e26d..17bc84d 100644 (file)
--- a/drivers/gpu/drm/xe/xe_vram_freq.c
+++ b/drivers/gpu/drm/xe/xe_vram_freq.c
@@ -34,7 +34,7 @@ static ssize_t max_freq_show(struct device *dev, struct device_attribute *attr,
                             char *buf)
 {
        struct xe_tile *tile = dev_to_tile(dev);
-       u32 val, mbox;
+       u32 val = 0, mbox;
        int err;
 
        mbox = REG_FIELD_PREP(PCODE_MB_COMMAND, PCODE_FREQUENCY_CONFIG)
@@ -56,7 +56,7 @@ static ssize_t min_freq_show(struct device *dev, struct device_attribute *attr,
                             char *buf)
 {
        struct xe_tile *tile = dev_to_tile(dev);
-       u32 val, mbox;
+       u32 val = 0, mbox;
        int err;
 
        mbox = REG_FIELD_PREP(PCODE_MB_COMMAND, PCODE_FREQUENCY_CONFIG)