On 12/3/21 4:13 AM, Dan Carpenter wrote:
Hello Vinod Koul,
The patch f533a035e4da: "ASoC: Intel: mrfld - create separate module for pci part" from Nov 4, 2014, leads to the following Smatch static checker warning:
sound/soc/intel/atom/sst/sst_pci.c:102 sst_platform_get_resources() warn: resource freed on success: 'ctx->pci'
sound/soc/intel/atom/sst/sst_pci.c 25 static int sst_platform_get_resources(struct intel_sst_drv *ctx) 26 { 27 int ddr_base, ret = 0; 28 struct pci_dev *pci = ctx->pci; 29 30 ret = pci_request_regions(pci, SST_DRV_NAME); 31 if (ret) 32 return ret; 33 34 /* map registers */ 35 /* DDR base */ 36 if (ctx->dev_id == SST_MRFLD_PCI_ID) { 37 ctx->ddr_base = pci_resource_start(pci, 0); 38 /* check that the relocated IMR base matches with FW Binary */ 39 ddr_base = relocate_imr_addr_mrfld(ctx->ddr_base); 40 if (!ctx->pdata->lib_info) { 41 dev_err(ctx->dev, "lib_info pointer NULL\n"); 42 ret = -EINVAL; 43 goto do_release_regions; 44 } 45 if (ddr_base != ctx->pdata->lib_info->mod_base) { 46 dev_err(ctx->dev, 47 "FW LSP DDR BASE does not match with IFWI\n"); 48 ret = -EINVAL; 49 goto do_release_regions; 50 } 51 ctx->ddr_end = pci_resource_end(pci, 0); 52 53 ctx->ddr = pcim_iomap(pci, 0, 54 pci_resource_len(pci, 0)); 55 if (!ctx->ddr) { 56 ret = -EINVAL; 57 goto do_release_regions; 58 } 59 dev_dbg(ctx->dev, "sst: DDR Ptr %p\n", ctx->ddr); 60 } else { 61 ctx->ddr = NULL; 62 } 63 /* SHIM */ 64 ctx->shim_phy_add = pci_resource_start(pci, 1); 65 ctx->shim = pcim_iomap(pci, 1, pci_resource_len(pci, 1)); 66 if (!ctx->shim) { 67 ret = -EINVAL; 68 goto do_release_regions; 69 } 70 dev_dbg(ctx->dev, "SST Shim Ptr %p\n", ctx->shim); 71 72 /* Shared SRAM */ 73 ctx->mailbox_add = pci_resource_start(pci, 2); 74 ctx->mailbox = pcim_iomap(pci, 2, pci_resource_len(pci, 2)); 75 if (!ctx->mailbox) { 76 ret = -EINVAL; 77 goto do_release_regions; 78 } 79 dev_dbg(ctx->dev, "SRAM Ptr %p\n", ctx->mailbox); 80 81 /* IRAM */ 82 ctx->iram_end = pci_resource_end(pci, 3); 83 ctx->iram_base = pci_resource_start(pci, 3); 84 ctx->iram = pcim_iomap(pci, 3, pci_resource_len(pci, 3)); 85 if (!ctx->iram) { 86 ret = -EINVAL; 87 goto do_release_regions; 88 } 89 dev_dbg(ctx->dev, "IRAM Ptr %p\n", ctx->iram); 90 91 /* DRAM */ 92 ctx->dram_end = pci_resource_end(pci, 4); 93 ctx->dram_base = pci_resource_start(pci, 4); 94 ctx->dram = pcim_iomap(pci, 4, pci_resource_len(pci, 4)); 95 if (!ctx->dram) { 96 ret = -EINVAL; 97 goto do_release_regions; 98 } 99 dev_dbg(ctx->dev, "DRAM Ptr %p\n", ctx->dram); 100 do_release_regions: 101 pci_release_regions(pci); --> 102 return ret; 103 }
Surely there should be a "return 0;" before the do_release_regions: label? How does this code work?
Thanks for reporting this Dan. Yes this doesn't look good at all.
This PCI part is only used on Merrifield/Tangier, and I am not sure if anyone ever managed to make audio work with the upstream version of this driver. It's my understanding that this platform is no longer maintained by Intel, and the Edison Yocto code uses the SOF driver.
The Kconfig updated in 2018 hints at those limitations:
config SND_SST_ATOM_HIFI2_PLATFORM_PCI tristate "PCI HiFi2 (Merrifield) Platforms" depends on X86 && PCI select SND_SST_ATOM_HIFI2_PLATFORM help If you have a Intel Merrifield/Edison platform, then enable this option by saying Y or m. Distros will typically not enable this option: while Merrifield/Edison can run a mainline kernel with limited functionality it will require a firmware file which is not in the standard firmware tree
I would guess that indeed a return 0; is missing, but maybe it's time to remove this PCI code completely. I can't think of any user of the PCI parts of this driver.
Andy, Hans, Mark, Takashi, what do you think?