From: Mikulas Patocka <mpatocka@redhat.com>
Date: Sun, 3 Jun 2018 16:41:01 +0200
Subject: udl-kms: avoid prefetch
Git-commit: 58cba7c222e8c87bb6b61fcba21d1536145221b0
Patch-mainline: v4.19-rc1
References: FATE#326289 FATE#326079 FATE#326049 FATE#322398 FATE#326166

Modern processors can detect linear memory accesses and prefetch data
automatically, so there's no need to use prefetch.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Acked-by: Petr Tesarik <ptesarik@suse.com>
---
 drivers/gpu/drm/udl/udl_transfer.c |    7 -------
 1 file changed, 7 deletions(-)

--- a/drivers/gpu/drm/udl/udl_transfer.c
+++ b/drivers/gpu/drm/udl/udl_transfer.c
@@ -13,7 +13,6 @@
 #include <linux/module.h>
 #include <linux/slab.h>
 #include <linux/fb.h>
-#include <linux/prefetch.h>
 #include <asm/unaligned.h>
 
 #include <drm/drmP.h>
@@ -51,9 +50,6 @@ static int udl_trim_hline(const u8 *bbac
 	int start = width;
 	int end = width;
 
-	prefetch((void *) front);
-	prefetch((void *) back);
-
 	for (j = 0; j < width; j++) {
 		if (back[j] != front[j]) {
 			start = j;
@@ -140,8 +136,6 @@ static void udl_compress_hline16(
 		const u8 *cmd_pixel_start, *cmd_pixel_end = NULL;
 		uint16_t pixel_val16;
 
-		prefetchw((void *) cmd); /* pull in one cache line at least */
-
 		*cmd++ = 0xaf;
 		*cmd++ = 0x6b;
 		*cmd++ = (uint8_t) ((dev_addr >> 16) & 0xFF);
@@ -158,7 +152,6 @@ static void udl_compress_hline16(
 					(unsigned long)(pixel_end - pixel) >> log_bpp,
 					(unsigned long)(cmd_buffer_end - 1 - cmd) / 2) << log_bpp);
 
-		prefetch_range((void *) pixel, cmd_pixel_end - pixel);
 		pixel_val16 = get_pixel_val16(pixel, log_bpp);
 
 		while (pixel < cmd_pixel_end) {