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The compiler should be able to optimize the original code and avoid using any actual VLAs. Anyway this change is useful because it will avoid a false positives with -Wvla, it might also help the compiler generating better code. [1] https://lkml.org/lkml/2018/3/7/621 Signed-off-by: Salvatore Mesoraca --- drivers/gpu/drm/i915/i915_debugfs.c | 26 ++++++++++++++++---------- 1 file changed, 16 insertions(+), 10 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c index e968aea..bf0a8e3 100644 --- a/drivers/gpu/drm/i915/i915_debugfs.c +++ b/drivers/gpu/drm/i915/i915_debugfs.c @@ -4259,19 +4259,20 @@ static ssize_t cur_wm_latency_write(struct file *file, const char __user *ubuf, i915_cache_sharing_get, i915_cache_sharing_set, "%llu\n"); +#define CHERRYVIEW_SS_MAX 2 + static void cherryview_sseu_device_status(struct drm_i915_private *dev_priv, struct sseu_dev_info *sseu) { - int ss_max = 2; int ss; - u32 sig1[ss_max], sig2[ss_max]; + u32 sig1[CHERRYVIEW_SS_MAX], sig2[CHERRYVIEW_SS_MAX]; sig1[0] = I915_READ(CHV_POWER_SS0_SIG1); sig1[1] = I915_READ(CHV_POWER_SS1_SIG1); sig2[0] = I915_READ(CHV_POWER_SS0_SIG2); sig2[1] = I915_READ(CHV_POWER_SS1_SIG2); - for (ss = 0; ss < ss_max; ss++) { + for (ss = 0; ss < CHERRYVIEW_SS_MAX; ss++) { unsigned int eu_cnt; if (sig1[ss] & CHV_SS_PG_ENABLE) @@ -4290,15 +4291,17 @@ static void cherryview_sseu_device_status(struct drm_i915_private *dev_priv, } } +#define GEN10_S_MAX 6 +#define GEN10_SS_MAX 4 + static void gen10_sseu_device_status(struct drm_i915_private *dev_priv, struct sseu_dev_info *sseu) { const struct intel_device_info *info = INTEL_INFO(dev_priv); - int s_max = 6, ss_max = 4; int s, ss; - u32 s_reg[s_max], eu_reg[2 * s_max], eu_mask[2]; + u32 s_reg[GEN10_S_MAX], eu_reg[2 * GEN10_S_MAX], eu_mask[2]; - for (s = 0; s < s_max; s++) { + for (s = 0; s < GEN10_S_MAX; s++) { /* * FIXME: Valid SS Mask respects the spec and read * only valid bits for those registers, excluding reserverd @@ -4320,7 +4323,7 @@ static void gen10_sseu_device_status(struct drm_i915_private *dev_priv, GEN9_PGCTL_SSB_EU210_ACK | GEN9_PGCTL_SSB_EU311_ACK; - for (s = 0; s < s_max; s++) { + for (s = 0; s < GEN10_S_MAX; s++) { if ((s_reg[s] & GEN9_PGCTL_SLICE_ACK) == 0) /* skip disabled slice */ continue; @@ -4328,7 +4331,7 @@ static void gen10_sseu_device_status(struct drm_i915_private *dev_priv, sseu->slice_mask |= BIT(s); sseu->subslice_mask = info->sseu.subslice_mask; - for (ss = 0; ss < ss_max; ss++) { + for (ss = 0; ss < GEN10_SS_MAX; ss++) { unsigned int eu_cnt; if (!(s_reg[s] & (GEN9_PGCTL_SS_ACK(ss)))) @@ -4345,12 +4348,15 @@ static void gen10_sseu_device_status(struct drm_i915_private *dev_priv, } } +#define GEN9_S_MAX 3 +#define GEN9_SS_MAX 4 + static void gen9_sseu_device_status(struct drm_i915_private *dev_priv, struct sseu_dev_info *sseu) { - int s_max = 3, ss_max = 4; + int s_max = GEN9_S_MAX, ss_max = GEN9_SS_MAX; int s, ss; - u32 s_reg[s_max], eu_reg[2*s_max], eu_mask[2]; + u32 s_reg[GEN9_S_MAX], eu_reg[2*GEN9_S_MAX], eu_mask[2]; /* BXT has a single slice and at most 3 subslices. */ if (IS_GEN9_LP(dev_priv)) { -- 1.9.1