drivers/gpu/drm/bridge/analogix/anx7625.c:754:4: warning: Value stored to 'ret' is never read [clang-analyzer-deadcode.DeadStores]

From: kernel test robot
Date: Sun Aug 15 2021 - 10:29:46 EST

Next message: Jonathan Cameron: "Re: [PATCH v3 2/2] iio: potentiometer: Add driver support for AD5110"
Previous message: kernel test robot: "[tip:irq/urgent] BUILD SUCCESS 7a3dc4f35bf8e1a07e5c3f8ecc8ac923f48493fe"
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]

tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
head: 0aa78d17099b04fd9d36fe338af48ad6fe2d7fca
commit: c489573b5b6ce6442ad4658d9d5ec77839b91622 Merge drm/drm-next into drm-misc-next
date: 10 months ago
config: x86_64-randconfig-c001-20210813 (attached as .config)
compiler: clang version 14.0.0 (https://github.com/llvm/llvm-project 767496d19cb9a1fbba57ff08095faa161998ee36)
reproduce (this is a W=1 build):
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# install x86_64 cross compiling tool for clang build
# apt-get install binutils-x86-64-linux-gnu
# https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=c489573b5b6ce6442ad4658d9d5ec77839b91622
git remote add linus https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
git fetch --no-tags linus master
git checkout c489573b5b6ce6442ad4658d9d5ec77839b91622
# save the attached .config to linux build tree
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=x86_64 clang-analyzer

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@xxxxxxxxx>

clang-analyzer warnings: (new ones prefixed by >>)
7 warnings generated.
Suppressed 7 warnings (7 in non-user code).
Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well.
7 warnings generated.
Suppressed 7 warnings (7 in non-user code).
Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well.
6 warnings generated.
Suppressed 6 warnings (6 in non-user code).
Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well.
5 warnings generated.
Suppressed 5 warnings (5 in non-user code).
Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well.
5 warnings generated.
Suppressed 5 warnings (5 in non-user code).
Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well.
5 warnings generated.
Suppressed 5 warnings (5 in non-user code).
Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well.
5 warnings generated.
Suppressed 5 warnings (5 in non-user code).
Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well.
5 warnings generated.
Suppressed 5 warnings (5 in non-user code).
Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well.
15 warnings generated.
net/core/filter.c:1736:2: warning: Null pointer passed as 1st argument to memory set function [clang-analyzer-unix.cstring.NullArg]
memset(to, 0, len);
^
net/core/filter.c:9941:57: note: Passing value via 3rd parameter 'to'
return ____bpf_skb_load_bytes(reuse_kern->skb, offset, to, len);
^~
net/core/filter.c:9941:9: note: Calling '____bpf_skb_load_bytes'
return ____bpf_skb_load_bytes(reuse_kern->skb, offset, to, len);
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
net/core/filter.c:1725:15: note: Assuming 'offset' is <= 65535
if (unlikely(offset > 0xffff))
^
include/linux/compiler.h:78:42: note: expanded from macro 'unlikely'
# define unlikely(x) __builtin_expect(!!(x), 0)
^
net/core/filter.c:1725:2: note: Taking false branch
if (unlikely(offset > 0xffff))
^
net/core/filter.c:1729:15: note: Assuming 'ptr' is null
if (unlikely(!ptr))
^
include/linux/compiler.h:78:42: note: expanded from macro 'unlikely'
# define unlikely(x) __builtin_expect(!!(x), 0)
^
net/core/filter.c:1729:2: note: Taking true branch
if (unlikely(!ptr))
^
net/core/filter.c:1730:3: note: Control jumps to line 1736
goto err_clear;
^
net/core/filter.c:1736:2: note: Null pointer passed as 1st argument to memory set function
memset(to, 0, len);
^ ~~
net/core/filter.c:1770:2: warning: Null pointer passed as 1st argument to memory set function [clang-analyzer-unix.cstring.NullArg]
memset(to, 0, len);
^ ~~
net/core/filter.c:1756:15: note: Assuming 'offset' is <= 65535
if (unlikely(offset > 0xffff))
^
include/linux/compiler.h:78:42: note: expanded from macro 'unlikely'
# define unlikely(x) __builtin_expect(!!(x), 0)
^
net/core/filter.c:1756:2: note: Taking false branch
if (unlikely(offset > 0xffff))
^
net/core/filter.c:1759:15: note: Assuming field 'skb' is non-null
if (unlikely(!ctx->skb))
^
include/linux/compiler.h:78:42: note: expanded from macro 'unlikely'
# define unlikely(x) __builtin_expect(!!(x), 0)
^
net/core/filter.c:1759:2: note: Taking false branch
if (unlikely(!ctx->skb))
^
net/core/filter.c:1763:15: note: Assuming 'ptr' is null
if (unlikely(!ptr))
^
include/linux/compiler.h:78:42: note: expanded from macro 'unlikely'
# define unlikely(x) __builtin_expect(!!(x), 0)
^
net/core/filter.c:1763:2: note: Taking true branch
if (unlikely(!ptr))
^
net/core/filter.c:1764:3: note: Control jumps to line 1770
goto err_clear;
^
net/core/filter.c:1770:2: note: Null pointer passed as 1st argument to memory set function
memset(to, 0, len);
^ ~~
Suppressed 13 warnings (13 in non-user code).
Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well.
12 warnings generated.
Suppressed 12 warnings (12 in non-user code).
Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well.
7 warnings generated.
>> drivers/gpu/drm/bridge/analogix/anx7625.c:754:4: warning: Value stored to 'ret' is never read [clang-analyzer-deadcode.DeadStores]
ret = sp_tx_rst_aux(ctx);
^ ~~~~~~~~~~~~~~~~~~
drivers/gpu/drm/bridge/analogix/anx7625.c:754:4: note: Value stored to 'ret' is never read
ret = sp_tx_rst_aux(ctx);
^ ~~~~~~~~~~~~~~~~~~
Suppressed 6 warnings (6 in non-user code).
Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well.
8 warnings generated.
drivers/gpu/drm/bridge/analogix/analogix-anx78xx.c:536:2: warning: Value stored to 'err' is never read [clang-analyzer-deadcode.DeadStores]
err = anx78xx_clear_bits(anx78xx->map[I2C_IDX_TX_P2],
^ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/gpu/drm/bridge/analogix/analogix-anx78xx.c:536:2: note: Value stored to 'err' is never read
err = anx78xx_clear_bits(anx78xx->map[I2C_IDX_TX_P2],
^ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Suppressed 7 warnings (7 in non-user code).
Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well.
7 warnings generated.
Suppressed 7 warnings (7 in non-user code).
Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well.
8 warnings generated.
drivers/gpu/drm/bridge/analogix/analogix_dp_reg.c:424:2: warning: Value stored to 'reg' is never read [clang-analyzer-deadcode.DeadStores]
reg = readl(dp->reg_base + ANALOGIX_DP_SYS_CTL_3);
^
drivers/gpu/drm/bridge/analogix/analogix_dp_reg.c:424:2: note: Value stored to 'reg' is never read
Suppressed 7 warnings (6 in non-user code, 1 with check filters).
Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well.
5 warnings generated.
Suppressed 5 warnings (5 in non-user code).
Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well.
6 warnings generated.
Suppressed 6 warnings (6 in non-user code).
Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well.
8 warnings generated.
Suppressed 8 warnings (8 in non-user code).
Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well.
7 warnings generated.
Suppressed 7 warnings (7 in non-user code).
Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well.
7 warnings generated.
Suppressed 7 warnings (7 in non-user code).
Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well.
7 warnings generated.
Suppressed 7 warnings (7 in non-user code).
Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well.
7 warnings generated.
Suppressed 7 warnings (7 in non-user code).
Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well.
8 warnings generated.
Suppressed 8 warnings (8 in non-user code).
Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well.
7 warnings generated.
Suppressed 7 warnings (7 in non-user code).
Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well.
4 warnings generated.
Suppressed 4 warnings (4 in non-user code).
Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well.
5 warnings generated.
drivers/media/dvb-frontends/tda1004x.c:547:2: warning: Value stored to 'ret' is never read [clang-analyzer-deadcode.DeadStores]
ret = tda1004x_do_upload(state, fw->data, fw->size, TDA10046H_CODE_CPT, TDA10046H_CODE_IN);
^ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/media/dvb-frontends/tda1004x.c:547:2: note: Value stored to 'ret' is never read
ret = tda1004x_do_upload(state, fw->data, fw->size, TDA10046H_CODE_CPT, TDA10046H_CODE_IN);
^ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Suppressed 4 warnings (4 in non-user code).
Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well.
6 warnings generated.
drivers/media/dvb-frontends/sp887x.c:143:23: warning: Value stored to 'mem' during its initialization is never read [clang-analyzer-deadcode.DeadStores]
const unsigned char *mem = fw->data;
^~~ ~~~~~~~~
drivers/media/dvb-frontends/sp887x.c:143:23: note: Value stored to 'mem' during its initialization is never read
const unsigned char *mem = fw->data;
^~~ ~~~~~~~~
drivers/media/dvb-frontends/sp887x.c:458:39: warning: The result of the left shift is undefined because the left operand is negative [clang-analyzer-core.UndefinedBinaryOperatorResult]
(sp887x_readreg(state, 0xc07) << 6);
~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ^
drivers/media/dvb-frontends/sp887x.c:458:10: note: Calling 'sp887x_readreg'
(sp887x_readreg(state, 0xc07) << 6);
^~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/media/dvb-frontends/sp887x.c:84:6: note: Assuming the condition is true
if ((ret = i2c_transfer(state->i2c, msg, 2)) != 2) {
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/media/dvb-frontends/sp887x.c:84:2: note: Taking true branch
if ((ret = i2c_transfer(state->i2c, msg, 2)) != 2) {
^
drivers/media/dvb-frontends/sp887x.c:86:3: note: Returning the value -1
return -1;
^~~~~~~~~
drivers/media/dvb-frontends/sp887x.c:458:10: note: Returning from 'sp887x_readreg'
(sp887x_readreg(state, 0xc07) << 6);
^~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/media/dvb-frontends/sp887x.c:458:39: note: The result of the left shift is undefined because the left operand is negative
(sp887x_readreg(state, 0xc07) << 6);
~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ^
Suppressed 4 warnings (4 in non-user code).
Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well.
4 warnings generated.
Suppressed 4 warnings (4 in non-user code).
Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well.
4 warnings generated.
Suppressed 4 warnings (4 in non-user code).

vim +/ret +754 drivers/gpu/drm/bridge/analogix/anx7625.c

8bdfc5dae4e3ba Xin Ji 2020-09-18 720
8bdfc5dae4e3ba Xin Ji 2020-09-18 721 static int segments_edid_read(struct anx7625_data *ctx,
8bdfc5dae4e3ba Xin Ji 2020-09-18 722 u8 segment, u8 *buf, u8 offset)
8bdfc5dae4e3ba Xin Ji 2020-09-18 723 {
8bdfc5dae4e3ba Xin Ji 2020-09-18 724 u8 cnt;
8bdfc5dae4e3ba Xin Ji 2020-09-18 725 int ret;
8bdfc5dae4e3ba Xin Ji 2020-09-18 726 struct device *dev = &ctx->client->dev;
8bdfc5dae4e3ba Xin Ji 2020-09-18 727
8bdfc5dae4e3ba Xin Ji 2020-09-18 728 /* Write address only */
8bdfc5dae4e3ba Xin Ji 2020-09-18 729 ret = anx7625_reg_write(ctx, ctx->i2c.rx_p0_client,
8bdfc5dae4e3ba Xin Ji 2020-09-18 730 AP_AUX_ADDR_7_0, 0x30);
8bdfc5dae4e3ba Xin Ji 2020-09-18 731 ret |= anx7625_reg_write(ctx, ctx->i2c.rx_p0_client,
8bdfc5dae4e3ba Xin Ji 2020-09-18 732 AP_AUX_COMMAND, 0x04);
8bdfc5dae4e3ba Xin Ji 2020-09-18 733 ret |= anx7625_reg_write(ctx, ctx->i2c.rx_p0_client,
8bdfc5dae4e3ba Xin Ji 2020-09-18 734 AP_AUX_CTRL_STATUS,
8bdfc5dae4e3ba Xin Ji 2020-09-18 735 AP_AUX_CTRL_ADDRONLY | AP_AUX_CTRL_OP_EN);
8bdfc5dae4e3ba Xin Ji 2020-09-18 736
8bdfc5dae4e3ba Xin Ji 2020-09-18 737 ret |= wait_aux_op_finish(ctx);
8bdfc5dae4e3ba Xin Ji 2020-09-18 738 /* Write segment address */
8bdfc5dae4e3ba Xin Ji 2020-09-18 739 ret |= sp_tx_aux_wr(ctx, segment);
8bdfc5dae4e3ba Xin Ji 2020-09-18 740 /* Data read */
8bdfc5dae4e3ba Xin Ji 2020-09-18 741 ret |= anx7625_reg_write(ctx, ctx->i2c.rx_p0_client,
8bdfc5dae4e3ba Xin Ji 2020-09-18 742 AP_AUX_ADDR_7_0, 0x50);
8bdfc5dae4e3ba Xin Ji 2020-09-18 743 if (ret) {
8bdfc5dae4e3ba Xin Ji 2020-09-18 744 DRM_DEV_ERROR(dev, "IO error : aux initial fail.\n");
8bdfc5dae4e3ba Xin Ji 2020-09-18 745 return ret;
8bdfc5dae4e3ba Xin Ji 2020-09-18 746 }
8bdfc5dae4e3ba Xin Ji 2020-09-18 747
8bdfc5dae4e3ba Xin Ji 2020-09-18 748 for (cnt = 0; cnt <= EDID_TRY_CNT; cnt++) {
8bdfc5dae4e3ba Xin Ji 2020-09-18 749 sp_tx_aux_wr(ctx, offset);
8bdfc5dae4e3ba Xin Ji 2020-09-18 750 /* Set I2C read com 0x01 mot = 0 and read 16 bytes */
8bdfc5dae4e3ba Xin Ji 2020-09-18 751 ret = sp_tx_aux_rd(ctx, 0xf1);
8bdfc5dae4e3ba Xin Ji 2020-09-18 752
8bdfc5dae4e3ba Xin Ji 2020-09-18 753 if (ret) {
8bdfc5dae4e3ba Xin Ji 2020-09-18 @754 ret = sp_tx_rst_aux(ctx);
8bdfc5dae4e3ba Xin Ji 2020-09-18 755 DRM_DEV_ERROR(dev, "segment read fail, reset!\n");
8bdfc5dae4e3ba Xin Ji 2020-09-18 756 } else {
8bdfc5dae4e3ba Xin Ji 2020-09-18 757 ret = anx7625_reg_block_read(ctx, ctx->i2c.rx_p0_client,
8bdfc5dae4e3ba Xin Ji 2020-09-18 758 AP_AUX_BUFF_START,
8bdfc5dae4e3ba Xin Ji 2020-09-18 759 MAX_DPCD_BUFFER_SIZE, buf);
8bdfc5dae4e3ba Xin Ji 2020-09-18 760 if (ret > 0)
8bdfc5dae4e3ba Xin Ji 2020-09-18 761 break;
8bdfc5dae4e3ba Xin Ji 2020-09-18 762 }
8bdfc5dae4e3ba Xin Ji 2020-09-18 763 }
8bdfc5dae4e3ba Xin Ji 2020-09-18 764
8bdfc5dae4e3ba Xin Ji 2020-09-18 765 if (cnt > EDID_TRY_CNT)
8bdfc5dae4e3ba Xin Ji 2020-09-18 766 return -EIO;
8bdfc5dae4e3ba Xin Ji 2020-09-18 767
8bdfc5dae4e3ba Xin Ji 2020-09-18 768 return 0;
8bdfc5dae4e3ba Xin Ji 2020-09-18 769 }
8bdfc5dae4e3ba Xin Ji 2020-09-18 770

:::::: The code at line 754 was first introduced by commit
:::::: 8bdfc5dae4e3ba4d99dfb430ef43249e5f1b7730 drm/bridge: anx7625: Add anx7625 MIPI DSI/DPI to DP

:::::: TO: Xin Ji <xji@xxxxxxxxxxxxxxxx>
:::::: CC: Sam Ravnborg <sam@xxxxxxxxxxxx>

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@xxxxxxxxxxxx

Attachment: .config.gz
Description: application/gzip

Next message: Jonathan Cameron: "Re: [PATCH v3 2/2] iio: potentiometer: Add driver support for AD5110"
Previous message: kernel test robot: "[tip:irq/urgent] BUILD SUCCESS 7a3dc4f35bf8e1a07e5c3f8ecc8ac923f48493fe"
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]