From: kernel test robot <lkp@intel.com>
To: oe-kbuild@lists.linux.dev
Cc: lkp@intel.com, Julia Lawall <julia.lawall@inria.fr>
Subject: drivers/dma/bcm2835-dma.c:994:36-37: WARNING opportunity for min()
Date: Sun, 12 Jul 2026 01:53:14 +0800 [thread overview]
Message-ID: <202607120109.E43IucLt-lkp@intel.com> (raw)
BCC: lkp@intel.com
CC: oe-kbuild-all@lists.linux.dev
CC: linux-kernel@vger.kernel.org
TO: Johan Hovold <johan@kernel.org>
CC: Vinod Koul <vkoul@kernel.org>
Hi Johan,
First bad commit (maybe != root cause):
tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
head: dd3210c47e8d3ac6b4e9141fc68acc03b38c0ba3
commit: d3e1935fba8d71ef1889cbc2d6e2447cb829070f dmaengine: bcm2835: enable compile testing
date: 8 months ago
:::::: branch date: 16 hours ago
:::::: commit date: 8 months ago
config: hexagon-randconfig-r051-20260709 (https://download.01.org/0day-ci/archive/20260712/202607120109.E43IucLt-lkp@intel.com/config)
compiler: clang version 23.0.0git (https://github.com/llvm/llvm-project c279890c85da307abe34f10333442bbf72a60644)
If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Fixes: d3e1935fba8d ("dmaengine: bcm2835: enable compile testing")
| Reported-by: kernel test robot <lkp@intel.com>
| Reported-by: Julia Lawall <julia.lawall@inria.fr>
| Closes: https://lore.kernel.org/r/202607120109.E43IucLt-lkp@intel.com/
cocci warnings: (new ones prefixed by >>)
>> drivers/dma/bcm2835-dma.c:994:36-37: WARNING opportunity for min()
vim +994 drivers/dma/bcm2835-dma.c
9602a843cb3a16 Stefan Wahren 2024-12-04 898
96286b57669073 Florian Meier 2014-01-06 899 static int bcm2835_dma_probe(struct platform_device *pdev)
96286b57669073 Florian Meier 2014-01-06 900 {
96286b57669073 Florian Meier 2014-01-06 901 struct bcm2835_dmadev *od;
96286b57669073 Florian Meier 2014-01-06 902 void __iomem *base;
96286b57669073 Florian Meier 2014-01-06 903 int rc;
e2eca6389b031c Martin Sperl 2016-04-11 904 int i, j;
e2eca6389b031c Martin Sperl 2016-04-11 905 int irq[BCM2835_DMA_MAX_DMA_CHAN_SUPPORTED + 1];
e2eca6389b031c Martin Sperl 2016-04-11 906 int irq_flags;
96286b57669073 Florian Meier 2014-01-06 907 uint32_t chans_available;
e2eca6389b031c Martin Sperl 2016-04-11 908 char chan_name[BCM2835_DMA_CHAN_NAME_SIZE];
96286b57669073 Florian Meier 2014-01-06 909
96286b57669073 Florian Meier 2014-01-06 910 if (!pdev->dev.dma_mask)
96286b57669073 Florian Meier 2014-01-06 911 pdev->dev.dma_mask = &pdev->dev.coherent_dma_mask;
96286b57669073 Florian Meier 2014-01-06 912
96286b57669073 Florian Meier 2014-01-06 913 rc = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(32));
72503b25ee3638 Stefan Wahren 2019-07-16 914 if (rc) {
72503b25ee3638 Stefan Wahren 2019-07-16 915 dev_err(&pdev->dev, "Unable to set DMA mask\n");
96286b57669073 Florian Meier 2014-01-06 916 return rc;
72503b25ee3638 Stefan Wahren 2019-07-16 917 }
96286b57669073 Florian Meier 2014-01-06 918
96286b57669073 Florian Meier 2014-01-06 919 od = devm_kzalloc(&pdev->dev, sizeof(*od), GFP_KERNEL);
96286b57669073 Florian Meier 2014-01-06 920 if (!od)
96286b57669073 Florian Meier 2014-01-06 921 return -ENOMEM;
96286b57669073 Florian Meier 2014-01-06 922
96286b57669073 Florian Meier 2014-01-06 923 dma_set_max_seg_size(&pdev->dev, 0x3FFFFFFF);
96286b57669073 Florian Meier 2014-01-06 924
4b23603a251d24 Tudor Ambarus 2022-11-10 925 base = devm_platform_ioremap_resource(pdev, 0);
96286b57669073 Florian Meier 2014-01-06 926 if (IS_ERR(base))
96286b57669073 Florian Meier 2014-01-06 927 return PTR_ERR(base);
96286b57669073 Florian Meier 2014-01-06 928
96286b57669073 Florian Meier 2014-01-06 929 od->base = base;
96286b57669073 Florian Meier 2014-01-06 930
96286b57669073 Florian Meier 2014-01-06 931 dma_cap_set(DMA_SLAVE, od->ddev.cap_mask);
7f5ae3553685d5 Florian Meier 2014-01-17 932 dma_cap_set(DMA_PRIVATE, od->ddev.cap_mask);
96286b57669073 Florian Meier 2014-01-06 933 dma_cap_set(DMA_CYCLIC, od->ddev.cap_mask);
d9f094a02f3051 Martin Sperl 2016-03-16 934 dma_cap_set(DMA_MEMCPY, od->ddev.cap_mask);
96286b57669073 Florian Meier 2014-01-06 935 od->ddev.device_alloc_chan_resources = bcm2835_dma_alloc_chan_resources;
96286b57669073 Florian Meier 2014-01-06 936 od->ddev.device_free_chan_resources = bcm2835_dma_free_chan_resources;
96286b57669073 Florian Meier 2014-01-06 937 od->ddev.device_tx_status = bcm2835_dma_tx_status;
96286b57669073 Florian Meier 2014-01-06 938 od->ddev.device_issue_pending = bcm2835_dma_issue_pending;
96286b57669073 Florian Meier 2014-01-06 939 od->ddev.device_prep_dma_cyclic = bcm2835_dma_prep_dma_cyclic;
388cc7a281c06e Martin Sperl 2016-03-16 940 od->ddev.device_prep_slave_sg = bcm2835_dma_prep_slave_sg;
d9f094a02f3051 Martin Sperl 2016-03-16 941 od->ddev.device_prep_dma_memcpy = bcm2835_dma_prep_dma_memcpy;
39159bea78ed05 Maxime Ripard 2014-11-17 942 od->ddev.device_config = bcm2835_dma_slave_config;
39159bea78ed05 Maxime Ripard 2014-11-17 943 od->ddev.device_terminate_all = bcm2835_dma_terminate_all;
de92436ac40ffe Peter Ujfalusi 2017-11-14 944 od->ddev.device_synchronize = bcm2835_dma_synchronize;
b574368024670a Maxime Ripard 2014-11-17 945 od->ddev.src_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_4_BYTES);
b574368024670a Maxime Ripard 2014-11-17 946 od->ddev.dst_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_4_BYTES);
d9f094a02f3051 Martin Sperl 2016-03-16 947 od->ddev.directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV) |
d9f094a02f3051 Martin Sperl 2016-03-16 948 BIT(DMA_MEM_TO_MEM);
0fa5867e6a2c61 Martin Sperl 2016-03-16 949 od->ddev.residue_granularity = DMA_RESIDUE_GRANULARITY_BURST;
6f6869dc97e865 Lukas Wunner 2019-09-11 950 od->ddev.descriptor_reuse = true;
96286b57669073 Florian Meier 2014-01-06 951 od->ddev.dev = &pdev->dev;
96286b57669073 Florian Meier 2014-01-06 952 INIT_LIST_HEAD(&od->ddev.channels);
96286b57669073 Florian Meier 2014-01-06 953
96286b57669073 Florian Meier 2014-01-06 954 platform_set_drvdata(pdev, od);
96286b57669073 Florian Meier 2014-01-06 955
bf75703d0912da Lukas Wunner 2019-09-11 956 od->zero_page = dma_map_page_attrs(od->ddev.dev, ZERO_PAGE(0), 0,
bf75703d0912da Lukas Wunner 2019-09-11 957 PAGE_SIZE, DMA_TO_DEVICE,
bf75703d0912da Lukas Wunner 2019-09-11 958 DMA_ATTR_SKIP_CPU_SYNC);
bf75703d0912da Lukas Wunner 2019-09-11 959 if (dma_mapping_error(od->ddev.dev, od->zero_page)) {
bf75703d0912da Lukas Wunner 2019-09-11 960 dev_err(&pdev->dev, "Failed to map zero page\n");
bf75703d0912da Lukas Wunner 2019-09-11 961 return -ENOMEM;
bf75703d0912da Lukas Wunner 2019-09-11 962 }
bf75703d0912da Lukas Wunner 2019-09-11 963
96286b57669073 Florian Meier 2014-01-06 964 /* Request DMA channel mask from device tree */
96286b57669073 Florian Meier 2014-01-06 965 if (of_property_read_u32(pdev->dev.of_node,
96286b57669073 Florian Meier 2014-01-06 966 "brcm,dma-channel-mask",
96286b57669073 Florian Meier 2014-01-06 967 &chans_available)) {
96286b57669073 Florian Meier 2014-01-06 968 dev_err(&pdev->dev, "Failed to get channel mask\n");
96286b57669073 Florian Meier 2014-01-06 969 rc = -EINVAL;
96286b57669073 Florian Meier 2014-01-06 970 goto err_no_dma;
96286b57669073 Florian Meier 2014-01-06 971 }
96286b57669073 Florian Meier 2014-01-06 972
e2eca6389b031c Martin Sperl 2016-04-11 973 /* get irqs for each channel that we support */
e2eca6389b031c Martin Sperl 2016-04-11 974 for (i = 0; i <= BCM2835_DMA_MAX_DMA_CHAN_SUPPORTED; i++) {
e2eca6389b031c Martin Sperl 2016-04-11 975 /* skip masked out channels */
e2eca6389b031c Martin Sperl 2016-04-11 976 if (!(chans_available & (1 << i))) {
e2eca6389b031c Martin Sperl 2016-04-11 977 irq[i] = -1;
e2eca6389b031c Martin Sperl 2016-04-11 978 continue;
e2eca6389b031c Martin Sperl 2016-04-11 979 }
e2eca6389b031c Martin Sperl 2016-04-11 980
e2eca6389b031c Martin Sperl 2016-04-11 981 /* get the named irq */
e2eca6389b031c Martin Sperl 2016-04-11 982 snprintf(chan_name, sizeof(chan_name), "dma%i", i);
e2eca6389b031c Martin Sperl 2016-04-11 983 irq[i] = platform_get_irq_byname(pdev, chan_name);
e2eca6389b031c Martin Sperl 2016-04-11 984 if (irq[i] >= 0)
e2eca6389b031c Martin Sperl 2016-04-11 985 continue;
e2eca6389b031c Martin Sperl 2016-04-11 986
e2eca6389b031c Martin Sperl 2016-04-11 987 /* legacy device tree case handling */
e2eca6389b031c Martin Sperl 2016-04-11 988 dev_warn_once(&pdev->dev,
0eef727a47c5ea Martin Sperl 2016-04-22 989 "missing interrupt-names property in device tree - legacy interpretation is used\n");
e2eca6389b031c Martin Sperl 2016-04-11 990 /*
e2eca6389b031c Martin Sperl 2016-04-11 991 * in case of channel >= 11
e2eca6389b031c Martin Sperl 2016-04-11 992 * use the 11th interrupt and that is shared
e2eca6389b031c Martin Sperl 2016-04-11 993 */
e2eca6389b031c Martin Sperl 2016-04-11 @994 irq[i] = platform_get_irq(pdev, i < 11 ? i : 11);
e2eca6389b031c Martin Sperl 2016-04-11 995 }
e2eca6389b031c Martin Sperl 2016-04-11 996
e2eca6389b031c Martin Sperl 2016-04-11 997 /* get irqs for each channel */
e2eca6389b031c Martin Sperl 2016-04-11 998 for (i = 0; i <= BCM2835_DMA_MAX_DMA_CHAN_SUPPORTED; i++) {
e2eca6389b031c Martin Sperl 2016-04-11 999 /* skip channels without irq */
e2eca6389b031c Martin Sperl 2016-04-11 1000 if (irq[i] < 0)
e2eca6389b031c Martin Sperl 2016-04-11 1001 continue;
e2eca6389b031c Martin Sperl 2016-04-11 1002
e2eca6389b031c Martin Sperl 2016-04-11 1003 /* check if there are other channels that also use this irq */
e2eca6389b031c Martin Sperl 2016-04-11 1004 irq_flags = 0;
e2eca6389b031c Martin Sperl 2016-04-11 1005 for (j = 0; j <= BCM2835_DMA_MAX_DMA_CHAN_SUPPORTED; j++)
e2eca6389b031c Martin Sperl 2016-04-11 1006 if ((i != j) && (irq[j] == irq[i])) {
e2eca6389b031c Martin Sperl 2016-04-11 1007 irq_flags = IRQF_SHARED;
96286b57669073 Florian Meier 2014-01-06 1008 break;
e2eca6389b031c Martin Sperl 2016-04-11 1009 }
96286b57669073 Florian Meier 2014-01-06 1010
e2eca6389b031c Martin Sperl 2016-04-11 1011 /* initialize the channel */
e2eca6389b031c Martin Sperl 2016-04-11 1012 rc = bcm2835_dma_chan_init(od, i, irq[i], irq_flags);
96286b57669073 Florian Meier 2014-01-06 1013 if (rc)
96286b57669073 Florian Meier 2014-01-06 1014 goto err_no_dma;
96286b57669073 Florian Meier 2014-01-06 1015 }
96286b57669073 Florian Meier 2014-01-06 1016
96286b57669073 Florian Meier 2014-01-06 1017 dev_dbg(&pdev->dev, "Initialized %i DMA channels\n", i);
96286b57669073 Florian Meier 2014-01-06 1018
96286b57669073 Florian Meier 2014-01-06 1019 /* Device-tree DMA controller registration */
96286b57669073 Florian Meier 2014-01-06 1020 rc = of_dma_controller_register(pdev->dev.of_node,
96286b57669073 Florian Meier 2014-01-06 1021 bcm2835_dma_xlate, od);
96286b57669073 Florian Meier 2014-01-06 1022 if (rc) {
96286b57669073 Florian Meier 2014-01-06 1023 dev_err(&pdev->dev, "Failed to register DMA controller\n");
96286b57669073 Florian Meier 2014-01-06 1024 goto err_no_dma;
96286b57669073 Florian Meier 2014-01-06 1025 }
96286b57669073 Florian Meier 2014-01-06 1026
96286b57669073 Florian Meier 2014-01-06 1027 rc = dma_async_device_register(&od->ddev);
96286b57669073 Florian Meier 2014-01-06 1028 if (rc) {
96286b57669073 Florian Meier 2014-01-06 1029 dev_err(&pdev->dev,
96286b57669073 Florian Meier 2014-01-06 1030 "Failed to register slave DMA engine device: %d\n", rc);
96286b57669073 Florian Meier 2014-01-06 1031 goto err_no_dma;
96286b57669073 Florian Meier 2014-01-06 1032 }
96286b57669073 Florian Meier 2014-01-06 1033
96286b57669073 Florian Meier 2014-01-06 1034 dev_dbg(&pdev->dev, "Load BCM2835 DMA engine driver\n");
96286b57669073 Florian Meier 2014-01-06 1035
96286b57669073 Florian Meier 2014-01-06 1036 return 0;
96286b57669073 Florian Meier 2014-01-06 1037
96286b57669073 Florian Meier 2014-01-06 1038 err_no_dma:
96286b57669073 Florian Meier 2014-01-06 1039 bcm2835_dma_free(od);
96286b57669073 Florian Meier 2014-01-06 1040 return rc;
96286b57669073 Florian Meier 2014-01-06 1041 }
96286b57669073 Florian Meier 2014-01-06 1042
:::::: The code at line 994 was first introduced by commit
:::::: e2eca6389b031cdbbc4172eee89ce271c00cb672 dmaengine: bcm2835: use platform_get_irq_byname
:::::: TO: Martin Sperl <kernel@martin.sperl.org>
:::::: CC: Vinod Koul <vinod.koul@intel.com>
--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki
next reply other threads:[~2026-07-11 17:54 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-07-11 17:53 kernel test robot [this message]
-- strict thread matches above, loose matches on Subject: below --
2026-01-12 8:05 drivers/dma/bcm2835-dma.c:994:36-37: WARNING opportunity for min() kernel test robot
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