Hi Mikulas,
I love your patch! Perhaps something to improve:
[auto build test WARNING on drm/drm-next] [also build test WARNING on v4.17-rc7 next-20180601] [if your patch is applied to the wrong git tree, please drop us a note to help improve the system]
url: https://github.com/0day-ci/linux/commits/Mikulas-Patocka/USB-DisplayLink-pat... base: git://people.freedesktop.org/~airlied/linux.git drm-next reproduce: # apt-get install sparse make ARCH=x86_64 allmodconfig make C=1 CF=-D__CHECK_ENDIAN__
sparse warnings: (new ones prefixed by >>)
vim +1198 drivers/video/fbdev/udlfb.c
1171 1172 /* 1173 * Assumes &info->lock held by caller 1174 * Assumes no active clients have framebuffer open 1175 */ 1176 static int dlfb_realloc_framebuffer(struct dlfb_data *dlfb, struct fb_info *info, u32 new_len) 1177 { 1178 u32 old_len = info->fix.smem_len;
1179 unsigned char *old_fb = info->screen_base;
1180 unsigned char *new_fb; 1181 unsigned char *new_back = NULL; 1182 1183 new_len = PAGE_ALIGN(new_len); 1184 1185 if (new_len > old_len) { 1186 /* 1187 * Alloc system memory for virtual framebuffer 1188 */ 1189 new_fb = vmalloc(new_len); 1190 if (!new_fb) { 1191 dev_err(info->dev, "Virtual framebuffer alloc failed\n"); 1192 return -ENOMEM; 1193 } 1194 memset(new_fb, 0xff, new_len); 1195 1196 if (info->screen_base) { 1197 memcpy(new_fb, old_fb, old_len);
1198 dlfb_deferred_vfree(dlfb, info->screen_base);
1199 } 1200 1201 info->screen_base = new_fb; 1202 info->fix.smem_len = new_len; 1203 info->fix.smem_start = (unsigned long) new_fb; 1204 info->flags = udlfb_info_flags; 1205 1206 /* 1207 * Second framebuffer copy to mirror the framebuffer state 1208 * on the physical USB device. We can function without this. 1209 * But with imperfect damage info we may send pixels over USB 1210 * that were, in fact, unchanged - wasting limited USB bandwidth 1211 */ 1212 if (shadow) 1213 new_back = vzalloc(new_len); 1214 if (!new_back) 1215 dev_info(info->dev, 1216 "No shadow/backing buffer allocated\n"); 1217 else { 1218 dlfb_deferred_vfree(dlfb, dlfb->backing_buffer); 1219 dlfb->backing_buffer = new_back; 1220 } 1221 } 1222 return 0; 1223 } 1224
--- 0-DAY kernel test infrastructure Open Source Technology Center https://lists.01.org/pipermail/kbuild-all Intel Corporation