From 3d0f98fa66bc459d0ba516d1d46a0b22e3005244 Mon Sep 17 00:00:00 2001 From: Ashutosh Dixit Date: Fri, 2 Dec 2022 19:14:54 -0800 Subject: [PATCH] drm/i915/hwmon: Silence "mailbox access failed" warning in snb_pcode_read hwm_pcode_read_i1 is called during i915 load. This results in the following warning from snb_pcode_read because POWER_SETUP_SUBCOMMAND_READ_I1 is unsupported on DG1/DG2. [drm:snb_pcode_read [i915]] warning: pcode (read from mbox 47c) \ mailbox access failed for snb_pcode_read_p [i915]: -6 The code handles the unsupported command but the warning in dmesg is a red herring which has resulted in a couple of bugs being filed. Therefore silence the warning by avoiding calling snb_pcode_read_p for DG1/DG2. Signed-off-by: Ashutosh Dixit Reviewed-by: Anshuman Gupta Signed-off-by: Anshuman Gupta Link: https://patchwork.freedesktop.org/patch/msgid/20221203031454.1280538-1-ashutosh.dixit@intel.com --- drivers/gpu/drm/i915/i915_hwmon.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/gpu/drm/i915/i915_hwmon.c b/drivers/gpu/drm/i915/i915_hwmon.c index c588a17..cca7a43 100644 --- a/drivers/gpu/drm/i915/i915_hwmon.c +++ b/drivers/gpu/drm/i915/i915_hwmon.c @@ -293,6 +293,10 @@ static const struct hwmon_channel_info *hwm_gt_info[] = { /* I1 is exposed as power_crit or as curr_crit depending on bit 31 */ static int hwm_pcode_read_i1(struct drm_i915_private *i915, u32 *uval) { + /* Avoid ILLEGAL_SUBCOMMAND "mailbox access failed" warning in snb_pcode_read */ + if (IS_DG1(i915) || IS_DG2(i915)) + return -ENXIO; + return snb_pcode_read_p(&i915->uncore, PCODE_POWER_SETUP, POWER_SETUP_SUBCOMMAND_READ_I1, 0, uval); } -- 2.7.4