drm/radeon: properly validate the atpx interface

Some bioses don't set the function mask correctly
which caused required functions to be disabled.

Fixes:
https://bugzilla.kernel.org/show_bug.cgi?id=53111

Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org

1 files changed, 71 insertions, 2 deletions

diff --git a/drivers/gpu/drm/radeon/radeon_atpx_handler.c b/drivers/gpu/drm/radeon/radeon_atpx_handler.c
index 15f5ded65e0c..d96070bf8388 100644
--- a/drivers/gpu/drm/radeon/radeon_atpx_handler.c
+++ b/drivers/gpu/drm/radeon/radeon_atpx_handler.c
@@ -43,6 +43,12 @@ struct atpx_verify_interface {
         u32 function_bits;      /* supported functions bit vector */
 } __packed;
 
+struct atpx_px_params {
+        u16 size;               /* structure size in bytes (includes size field) */
+        u32 valid_flags;        /* which flags are valid */
+        u32 flags;              /* flags */
+} __packed;
+
 struct atpx_power_control {
         u16 size;
         u8 dgpu_state;
@@ -123,9 +129,61 @@ static void radeon_atpx_parse_functions(struct radeon_atpx_functions *f, u32 mas
 }
 
 /**
+ * radeon_atpx_validate_functions - validate ATPX functions
+ *
+ * @atpx: radeon atpx struct
+ *
+ * Validate that required functions are enabled (all asics).
+ * returns 0 on success, error on failure.
+ */
+static int radeon_atpx_validate(struct radeon_atpx *atpx)
+{
+        /* make sure required functions are enabled */
+        /* dGPU power control is required */
+        atpx->functions.power_cntl = true;
+
+        if (atpx->functions.px_params) {
+                union acpi_object *info;
+                struct atpx_px_params output;
+                size_t size;
+                u32 valid_bits;
+
+                info = radeon_atpx_call(atpx->handle, ATPX_FUNCTION_GET_PX_PARAMETERS, NULL);
+                if (!info)
+                        return -EIO;
+
+                memset(&output, 0, sizeof(output));
+
+                size = *(u16 *) info->buffer.pointer;
+                if (size < 10) {
+                        printk("ATPX buffer is too small: %zu\n", size);
+                        kfree(info);
+                        return -EINVAL;
+                }
+                size = min(sizeof(output), size);
+
+                memcpy(&output, info->buffer.pointer, size);
+
+                valid_bits = output.flags & output.valid_flags;
+                /* if separate mux flag is set, mux controls are required */
+                if (valid_bits & ATPX_SEPARATE_MUX_FOR_I2C) {
+                        atpx->functions.i2c_mux_cntl = true;
+                        atpx->functions.disp_mux_cntl = true;
+                }
+                /* if any outputs are muxed, mux controls are required */
+                if (valid_bits & (ATPX_CRT1_RGB_SIGNAL_MUXED |
+                                  ATPX_TV_SIGNAL_MUXED |
+                                  ATPX_DFP_SIGNAL_MUXED))
+                        atpx->functions.disp_mux_cntl = true;
+
+                kfree(info);
+        }
+        return 0;
+}
+
+/**
  * radeon_atpx_verify_interface - verify ATPX
  *
- * @handle: acpi handle
  * @atpx: radeon atpx struct
  *
  * Execute the ATPX_FUNCTION_VERIFY_INTERFACE ATPX function
@@ -406,8 +464,19 @@ static bool radeon_atpx_pci_probe_handle(struct pci_dev *pdev)
  */
 static int radeon_atpx_init(void)
 {
+        int r;
+
         /* set up the ATPX handle */
-        return radeon_atpx_verify_interface(&radeon_atpx_priv.atpx);
+        r = radeon_atpx_verify_interface(&radeon_atpx_priv.atpx);
+        if (r)
+                return r;
+
+        /* validate the atpx setup */
+        r = radeon_atpx_validate(&radeon_atpx_priv.atpx);
+        if (r)
+                return r;
+
+        return 0;
 }
 
 /**