From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dan Carpenter Subject: re: HID: Introduce hidpp, a module to handle Logitech hid++ devices Date: Fri, 31 Oct 2014 12:15:09 +0300 Message-ID: <20141031091509.GB11252@mwanda> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from aserp1040.oracle.com ([141.146.126.69]:40348 "EHLO aserp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752765AbaJaJPW (ORCPT ); Fri, 31 Oct 2014 05:15:22 -0400 Content-Disposition: inline Sender: linux-input-owner@vger.kernel.org List-Id: linux-input@vger.kernel.org To: benjamin.tissoires@redhat.com Cc: linux-input@vger.kernel.org Hello Benjamin Tissoires, The patch 2f31c5252910: "HID: Introduce hidpp, a module to handle Logitech hid++ devices" from Sep 30, 2014, leads to the following static checker warning: drivers/hid/hid-logitech-hidpp.c:359 hidpp_root_get_protocol_version() warn: should this return really be negated? drivers/hid/hid-logitech-hidpp.c 342 static int hidpp_root_get_protocol_version(struct hidpp_device *hidpp) 343 { 344 struct hidpp_report response; 345 int ret; 346 347 ret = hidpp_send_fap_command_sync(hidpp, 348 HIDPP_PAGE_ROOT_IDX, 349 CMD_ROOT_GET_PROTOCOL_VERSION, 350 NULL, 0, &response); 351 352 if (ret == 1) { ^^^^^^^^ What does the "1" mean? Magic numbers are bad, yada yada yada. 353 hidpp->protocol_major = 1; 354 hidpp->protocol_minor = 0; 355 return 0; 356 } 357 358 if (ret) 359 return -ret; ^^^^^^^^^^^ This is wrong. The real problem is that hidpp_send_fap_command_sync() mixes normal and custom error codes. The callers are inconsistent in how they deal with it. 360 361 hidpp->protocol_major = response.fap.params[0]; 362 hidpp->protocol_minor = response.fap.params[1]; 363 364 return ret; 365 } See also: drivers/hid/hid-logitech-hidpp.c:398 hidpp_devicenametype_get_count() warn: should this return really be negated? drivers/hid/hid-logitech-hidpp.c:417 hidpp_devicenametype_get_device_name() warn: should this return really be negated? drivers/hid/hid-logitech-hidpp.c:524 hidpp_touchpad_get_raw_info() warn: should this return really be negated? regards, dan carpenter