[PATCH] intelfb: reduce stack usage

[PATCH] intelfb: reduce stack usage

[Randy.Dunlap]

Antonino A. Daplas a écrit:
> Using kmalloc() should be acceptable.  I'll CC the author. 
---

Reduce stack usage in intelfb_set_par() from 2404 bytes
(on x86-32) to 12 bytes.

Signed-off-by: Randy Dunlap <rddunlap@osdl.org>

diffstat:=
 drivers/video/intelfb/intelfbdrv.c |   25 ++++++++++++++++---------
 1 files changed, 16 insertions(+), 9 deletions(-)

diff -Naurp ./drivers/video/intelfb/intelfbdrv.c~intelfb_stack ./drivers/video/intelfb/intelfbdrv.c
--- ./drivers/video/intelfb/intelfbdrv.c~intelfb_stack	2004-12-19 15:19:41.277527280 -0800
+++ ./drivers/video/intelfb/intelfbdrv.c	2004-12-19 20:58:17.018065272 -0800
@@ -1234,8 +1234,7 @@ intelfb_check_var(struct fb_var_screenin
 static int
 intelfb_set_par(struct fb_info *info)
 {
-	struct intelfb_hwstate hw;
-
+	struct intelfb_hwstate *hw;
         struct intelfb_info *dinfo = GET_DINFO(info);
 
 	if (FIXED_MODE(dinfo)) {
@@ -1243,6 +1242,10 @@ intelfb_set_par(struct fb_info *info)
 		return -EINVAL;
 	}
 
+	hw = kmalloc(sizeof(*hw), GFP_ATOMIC);
+	if (!hw)
+		return -ENOMEM;
+
 	DBG_MSG("intelfb_set_par (%dx%d-%d)\n", info->var.xres,
 		info->var.yres, info->var.bits_per_pixel);
 
@@ -1251,15 +1254,15 @@ intelfb_set_par(struct fb_info *info)
 	if (dinfo->accel)
 		intelfbhw_2d_stop(dinfo);
 
-	hw = dinfo->save_state;
-	if (intelfbhw_mode_to_hw(dinfo, &hw, &info->var))
-		return -EINVAL;
-	if (intelfbhw_program_mode(dinfo, &hw, 0))
-		return -EINVAL;
+	memcpy(hw, &dinfo->save_state, sizeof(*hw));
+	if (intelfbhw_mode_to_hw(dinfo, hw, &info->var))
+		goto invalid_mode;
+	if (intelfbhw_program_mode(dinfo, hw, 0))
+		goto invalid_mode;
 
 #if REGDUMP > 0
-	intelfbhw_read_hw_state(dinfo, &hw, 0);
-	intelfbhw_print_hw_state(dinfo, &hw);
+	intelfbhw_read_hw_state(dinfo, hw, 0);
+	intelfbhw_print_hw_state(dinfo, hw);
 #endif
 
 	update_dinfo(dinfo, &info->var);
@@ -1278,7 +1281,11 @@ intelfb_set_par(struct fb_info *info)
 	} else {
 		info->flags = FBINFO_DEFAULT | FBINFO_HWACCEL_YPAN;
 	}
+	kfree(hw);
 	return 0;
+invalid_mode:
+	kfree(hw);
+	return -EINVAL;
 }
 
 static int

---


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