i965: Make intel_get_param return an int

This will fix the spurious error message: "Failed to query GPU properties."
that was unintentionally added in cc01b63d730.

This patch changes the function to return an int so that the caller is able to
do stuff based on the return value.

The equivalent of this patch was in the original series that fixed up the
warning, but I dropped it at the last moment. It is required to make the desired
behavior of not warning when trying to query GPU properties from the kernel
unless there is something the user can do about it.

v2: Use strerror (Jason)
Make EINVAL check similar in all places (Ian)

NOTE: Broadwell appears to actually have some issue where the kernel returns
ENODEV when it shouldn't be. I will investigate this separately.

Reported-by: Chris Forbes <chrisf@ijw.co.nz>
Signed-off-by: Ben Widawsky <ben@bwidawsk.net>
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
Reviewed-by: Alejandro Piñeiro <apinheiro@igalia.com>

diff --git a/src/mesa/drivers/dri/i965/intel_screen.c b/src/mesa/drivers/dri/i965/intel_screen.c
index dbec82f..db9d94d 100644 (file)
--- a/src/mesa/drivers/dri/i965/intel_screen.c
+++ b/src/mesa/drivers/dri/i965/intel_screen.c
@@ -932,7 +932,7 @@ static const __DRIextension *intelRobustScreenExtensions[] = {
     NULL
 };
 
-static bool
+static int
 intel_get_param(__DRIscreen *psp, int param, int *value)
 {
    int ret;
@@ -943,20 +943,17 @@ intel_get_param(__DRIscreen *psp, int param, int *value)
    gp.value = value;
 
    ret = drmCommandWriteRead(psp->fd, DRM_I915_GETPARAM, &gp, sizeof(gp));
-   if (ret) {
-      if (ret != -EINVAL)
+   if (ret < 0 && ret != -EINVAL)
         _mesa_warning(NULL, "drm_i915_getparam: %d", ret);
-      return false;
-   }
 
-   return true;
+   return ret;
 }
 
 static bool
 intel_get_boolean(__DRIscreen *psp, int param)
 {
    int value = 0;
-   return intel_get_param(psp, param, &value) && value;
+   return (intel_get_param(psp, param, &value) == 0) && value;
 }
 
 static void
@@ -1093,12 +1090,12 @@ intel_detect_sseu(struct intel_screen *intelScreen)
 
    ret = intel_get_param(intelScreen->driScrnPriv, I915_PARAM_SUBSLICE_TOTAL,
                          &intelScreen->subslice_total);
-   if (ret != -EINVAL)
+   if (ret < 0 && ret != -EINVAL)
       goto err_out;
 
    ret = intel_get_param(intelScreen->driScrnPriv,
                          I915_PARAM_EU_TOTAL, &intelScreen->eu_total);
-   if (ret != -EINVAL)
+   if (ret < 0 && ret != -EINVAL)
       goto err_out;
 
    /* Without this information, we cannot get the right Braswell brandstrings,
@@ -1114,7 +1111,7 @@ intel_detect_sseu(struct intel_screen *intelScreen)
 err_out:
    intelScreen->subslice_total = -1;
    intelScreen->eu_total = -1;
-   _mesa_warning(NULL, "Failed to query GPU properties.\n");
+   _mesa_warning(NULL, "Failed to query GPU properties (%s).\n", strerror(ret));
 }
 
 static bool