On Thu, 2017-12-21 at 05:52 +0800, kbuild test robot wrote: > Hi Philipp, > > I love your patch! Perhaps something to improve: > > [auto build test WARNING on linuxtv-media/master] > [also build test WARNING on v4.15-rc4 next-20171220] > [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/Philipp-Zabel/media-dt-bindings-coda-Add-compatible-for-CodaHx4-on-i-MX51/20171221-050217 > base: git://linuxtv.org/media_tree.git master > config: x86_64-allmodconfig (attached as .config) > compiler: gcc-7 (Debian 7.2.0-12) 7.2.1 20171025 > reproduce: > # save the attached .config to linux build tree > make ARCH=x86_64 > > Note: it may well be a FALSE warning.
I think it is. > FWIW you are at least aware of it now. > http://gcc.gnu.org/wiki/Better_Uninitialized_Warnings > > All warnings (new ones prefixed by >>): > > drivers/media/platform/coda/coda-bit.c: In function 'coda_setup_iram': > > > drivers/media/platform/coda/coda-bit.c:648:28: warning: 'me_bits' may be > > > used uninitialized in this function [-Wmaybe-uninitialized] > > iram_info->axi_sram_use |= me_bits; > ^~ > > vim +/me_bits +648 drivers/media/platform/coda/coda-bit.c > > 588 > 589 static void coda_setup_iram(struct coda_ctx *ctx) > 590 { > 591 struct coda_iram_info *iram_info = &ctx->iram_info; > 592 struct coda_dev *dev = ctx->dev; > 593 int w64, w128; > 594 int mb_width; > 595 int dbk_bits; > 596 int bit_bits; > 597 int ip_bits; > 598 int me_bits; > 599 > 600 memset(iram_info, 0, sizeof(*iram_info)); > 601 iram_info->next_paddr = dev->iram.paddr; > 602 iram_info->remaining = dev->iram.size; > 603 > 604 if (!dev->iram.vaddr) > 605 return; > 606 > 607 switch (dev->devtype->product) { > 608 case CODA_HX4: > 609 dbk_bits = CODA7_USE_HOST_DBK_ENABLE; > 610 bit_bits = CODA7_USE_HOST_BIT_ENABLE; > 611 ip_bits = CODA7_USE_HOST_IP_ENABLE; > 612 me_bits = CODA7_USE_HOST_ME_ENABLE; > 613 break; > 614 case CODA_7541: > 615 dbk_bits = CODA7_USE_HOST_DBK_ENABLE | > CODA7_USE_DBK_ENABLE; > 616 bit_bits = CODA7_USE_HOST_BIT_ENABLE | > CODA7_USE_BIT_ENABLE; > 617 ip_bits = CODA7_USE_HOST_IP_ENABLE | > CODA7_USE_IP_ENABLE; > 618 me_bits = CODA7_USE_HOST_ME_ENABLE | > CODA7_USE_ME_ENABLE; > 619 break; > 620 case CODA_960: > 621 dbk_bits = CODA9_USE_HOST_DBK_ENABLE | > CODA9_USE_DBK_ENABLE; > 622 bit_bits = CODA9_USE_HOST_BIT_ENABLE | > CODA7_USE_BIT_ENABLE; > 623 ip_bits = CODA9_USE_HOST_IP_ENABLE | > CODA7_USE_IP_ENABLE; This is the only path that continues with me_bits uninitialized. In this case ... > 624 break; > 625 default: /* CODA_DX6 */ > 626 return; > 627 } > 628 > 629 if (ctx->inst_type == CODA_INST_ENCODER) { > 630 struct coda_q_data *q_data_src; > 631 > 632 q_data_src = get_q_data(ctx, > V4L2_BUF_TYPE_VIDEO_OUTPUT); > 633 mb_width = DIV_ROUND_UP(q_data_src->width, 16); > 634 w128 = mb_width * 128; > 635 w64 = mb_width * 64; > 636 > 637 /* Prioritize in case IRAM is too small for > everything */ > 638 if (dev->devtype->product == CODA_HX4 || > 639 dev->devtype->product == CODA_7541) { > 640 iram_info->search_ram_size = > round_up(mb_width * 16 * > 641 > 36 + 2048, 1024); > 642 iram_info->search_ram_paddr = > coda_iram_alloc(iram_info, > 643 > iram_info->search_ram_size); > 644 if (!iram_info->search_ram_paddr) { > 645 pr_err("IRAM is smaller than > the search ram size\n"); > 646 goto out; > 647 } > > 648 iram_info->axi_sram_use |= me_bits; ... dev->devtype->product == CODA_960, and this use of me_bits is never reached. regards Philipp
