Hi Abhilash, FYI, the error/warning still remains. tree: https://github.com/intel/linux-intel-lts.git 4.19/android_r head: 072f407465e8e25a3c2c22590e1ab72ccf335151 commit: 570daed7a2103fdef146a86d30df849a01ea01a9 [18603/22631] usb: xhci: dbc: Add a dbc raw driver to provide a raw interface on DbC config: alpha-allmodconfig (attached as .config) compiler: alpha-linux-gcc (GCC) 9.3.0 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 # https://github.com/intel/linux-intel-lts/commit/570daed7a2103fdef146a86d3... git remote add intel-linux-intel-lts https://github.com/intel/linux-intel-lts.git git fetch --no-tags intel-linux-intel-lts 4.19/android_r git checkout 570daed7a2103fdef146a86d30df849a01ea01a9 # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=alpha If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; All errors (new ones prefixed by >>): drivers/usb/host/xhci-dbgraw.c:48:21: warning: no previous prototype for 'xhci_dbc_alloc_requests' [-Wmissing-prototypes] 48 | struct dbc_request *xhci_dbc_alloc_requests(struct dbc_ep *dep, | ^~~~~~~~~~~~~~~~~~~~~~~ drivers/usb/host/xhci-dbgraw.c: In function 'dbc_read': 144 | r = copy_to_user(buf, req->buf, xfer); | ^~~~~~~~~~~~ | sg_copy_to_buffer drivers/usb/host/xhci-dbgraw.c: In function 'dbc_write': 185 | ret = copy_from_user(req->buf, buf, xfer); | ^~~~~~~~~~~~~~ | kfifo_from_user In file included from drivers/usb/host/xhci-dbgraw.c:13: drivers/usb/host/xhci-dbgraw.c: At top level: include/linux/module.h:133:6: warning: 'init_module' specifies less restrictive attribute than its target 'xhci_dbc_raw_init': 'cold' [-Wmissing-attributes] 133 | int init_module(void) __attribute__((alias(#initfn))); | ^~~~~~~~~~~ include/linux/module.h:123:28: note: in expansion of macro 'module_init' 123 | #define late_initcall(fn) module_init(fn) | ^~~~~~~~~~~ drivers/usb/host/xhci-dbgraw.c:360:1: note: in expansion of macro 'late_initcall' 360 | late_initcall(xhci_dbc_raw_init); | ^~~~~~~~~~~~~ drivers/usb/host/xhci-dbgraw.c:350:19: note: 'init_module' target declared here 350 | static int __init xhci_dbc_raw_init(void) | ^~~~~~~~~~~~~~~~~ In file included from drivers/usb/host/xhci-dbgraw.c:13: include/linux/module.h:139:7: warning: 'cleanup_module' specifies less restrictive attribute than its target 'xhci_dbc_raw_fini': 'cold' [-Wmissing-attributes] 139 | void cleanup_module(void) __attribute__((alias(#exitfn))); | ^~~~~~~~~~~~~~ drivers/usb/host/xhci-dbgraw.c:361:1: note: in expansion of macro 'module_exit' 361 | module_exit(xhci_dbc_raw_fini); | ^~~~~~~~~~~ drivers/usb/host/xhci-dbgraw.c:355:20: note: 'cleanup_module' target declared here 355 | static void __exit xhci_dbc_raw_fini(void) | ^~~~~~~~~~~~~~~~~ cc1: some warnings being treated as errors vim +144 drivers/usb/host/xhci-dbgraw.c 47 49 void (*fn)(struct xhci_hcd *, struct dbc_request *)) 50 { 51 struct dbc_request *req; 52 53 req = dbc_alloc_request(dep, GFP_KERNEL); 54 if (!req) 55 return req; 56 57 req->length = DBC_RAW_BULK_BUFFER_SIZE; 58 req->buf = kmalloc(req->length, GFP_KERNEL); 59 if (!req->buf) 60 xhci_dbc_free_req(dep, req); 61 62 req->complete = fn; 63 64 return req; 65 } 66 67 static void dbc_complete_in(struct xhci_hcd *xhci, 68 struct dbc_request *req) 69 { 70 struct xhci_dbc *dbc = (struct xhci_dbc *) xhci->dbc; 71 struct dbc_dev *dev = (struct dbc_dev *) dbc->func_priv; 72 73 if (req->status) 74 dev->error = req->status; 75 76 wake_up(&dev->write_wq); 77 } 78 79 static void dbc_complete_out(struct xhci_hcd *xhci, 80 struct dbc_request *req) 81 { 82 struct xhci_dbc *dbc = (struct xhci_dbc *) xhci->dbc; 83 struct dbc_dev *dev = (struct dbc_dev *) dbc->func_priv; 84 85 if (req->status) 86 dev->error = req->status; 87 88 wake_up(&dev->read_wq); 89 } 90 91 static ssize_t dbc_read(struct file *fp, char __user *buf, 92 size_t count, loff_t *pos) 93 { 94 int status = 0; 95 struct dbc_dev *dev = (struct dbc_dev *) fp->private_data; 96 struct xhci_dbc *dbc = dev->dbc; 97 struct dbc_request *req; 98 struct dbc_port *port = &dbc->port; 99 int r = count, xfer; 100 int ret; 101 102 if (dbc->state != DS_CONFIGURED) 103 return -EAGAIN; 104 105 port->in = get_in_ep(dbc->xhci); 106 107 mutex_lock(&dev->read_excl); 108 109 req = xhci_dbc_alloc_requests(port->in, dbc_complete_out); 110 if (!req) { 111 r = -ENOMEM; 112 goto alloc_fail; 113 } 114 115 req->actual = 0; 116 117 xfer = min_t(size_t, count, DBC_RAW_BULK_BUFFER_SIZE); 118 req->length = xfer; 119 120 status = dbc_ep_queue(port->in, req, GFP_ATOMIC); 121 if (status) { 122 dev->error = status; 123 r = status; 124 goto request_fail; 125 } 126 127 ret = wait_event_interruptible(dev->read_wq, 128 (req->status != -EINPROGRESS)); 129 130 if (ret < 0) { 131 r = ret; 132 goto request_fail; 133 } 134 135 if (dev->error) { 136 r = dev->error; 137 goto request_fail; 138 } 139 140 xfer = (req->actual < count) ? req->actual : count; 141 if (!req->actual) { 142 r = 0; 143 } else { 145 if (!r) 146 r = xfer; 147 } 148 149 request_fail: 150 xhci_dbc_free_req(port->in, req); 151 alloc_fail: 152 mutex_unlock(&dev->read_excl); 153 154 return r; 155 } 156 157 static ssize_t dbc_write(struct file *fp, const char __user *buf, 158 size_t count, loff_t *pos) 159 { 160 int status = 0; 161 struct dbc_dev *dev = (struct dbc_dev *) fp->private_data; 162 struct xhci_dbc *dbc = dev->dbc; 163 struct dbc_request *req = 0; 164 struct dbc_port *port = &dbc->port; 165 int r = count, xfer; 166 int ret; 167 168 if (dbc->state != DS_CONFIGURED) 169 return -EAGAIN; 170 171 port->out = get_out_ep(dbc->xhci); 172 173 mutex_lock(&dev->write_excl); 174 175 /* get an idle tx request to use */ 176 req = xhci_dbc_alloc_requests(port->out, dbc_complete_in); 177 if (!req) { 178 r = -ENOMEM; 179 goto alloc_fail; 180 } 181 182 req->actual = 0; 183 xfer = min_t(size_t, count, DBC_RAW_BULK_BUFFER_SIZE); 184 186 if (ret) { 187 r = ret; 188 goto request_fail; 189 } 190 r = xfer; 191 req->length = xfer; 192 status = dbc_ep_queue(port->out, req, GFP_ATOMIC); 193 if (status) { 194 dev->error = status; 195 r = status; 196 goto request_fail; 197 } 198 199 ret = wait_event_interruptible(dev->write_wq, 200 (req->status != -EINPROGRESS)); 201 if (ret < 0) 202 r = ret; 203 204 request_fail: 205 xhci_dbc_free_req(port->out, req); 206 alloc_fail: 207 mutex_unlock(&dev->write_excl); 208 209 return r; 210 } 211 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org