Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751997AbdGLSUD (ORCPT ); Wed, 12 Jul 2017 14:20:03 -0400 Received: from mail-pg0-f66.google.com ([74.125.83.66]:34707 "EHLO mail-pg0-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751075AbdGLSUB (ORCPT ); Wed, 12 Jul 2017 14:20:01 -0400 Date: Wed, 12 Jul 2017 11:19:57 -0700 From: Dmitry Torokhov To: Nick Desaulniers Cc: linux-input@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v4] Input: mousedev - fix implicit conversion warning Message-ID: <20170712181957.GA16112@dtor-ws> References: <20170526154029.9405-1-nick.desaulniers@gmail.com> <20170530054151.16639-1-nick.desaulniers@gmail.com> <20170625180609.GA8697@dtor-ws> <20170712065710.7rn43l6uujsbboju@lostoracle.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20170712065710.7rn43l6uujsbboju@lostoracle.net> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4560 Lines: 150 On Tue, Jul 11, 2017 at 11:57:10PM -0700, Nick Desaulniers wrote: > Hi Dmitry, did you get a chance to merge the sugguested revision, yet? Sorry, no, as it was broken (we lost the assignment to the bytes 2 and 3 of the PS/2 data stream). Here is the version that seems to work, but at this time I guess I'll push it out to 4.14. -- Dmitry Input: mousedev - fix implicit conversion warning From: Nick Desaulniers Clang warns: drivers/input/mousedev.c:653:63: error: implicit conversion from 'int' to 'signed char' changes value from 200 to -56 [-Wconstant-conversion] client->ps2[1] = 0x60; client->ps2[2] = 3; client->ps2[3] = 200; ~ ^~~ As the PS2 data is really a stream of bytes, let's switch to using u8 type for it, which silences this warning. Signed-off-by: Nick Desaulniers Patchwork-Id: 9753771 Signed-off-by: Dmitry Torokhov --- drivers/input/mousedev.c | 62 +++++++++++++++++++++++++--------------------- 1 file changed, 34 insertions(+), 28 deletions(-) diff --git a/drivers/input/mousedev.c b/drivers/input/mousedev.c index 0e0ff84088fd..114730a0c3fa 100644 --- a/drivers/input/mousedev.c +++ b/drivers/input/mousedev.c @@ -15,6 +15,7 @@ #define MOUSEDEV_MINORS 31 #define MOUSEDEV_MIX 63 +#include #include #include #include @@ -103,7 +104,7 @@ struct mousedev_client { spinlock_t packet_lock; int pos_x, pos_y; - signed char ps2[6]; + u8 ps2[6]; unsigned char ready, buffer, bufsiz; unsigned char imexseq, impsseq; enum mousedev_emul mode; @@ -291,11 +292,10 @@ static void mousedev_notify_readers(struct mousedev *mousedev, } client->pos_x += packet->dx; - client->pos_x = client->pos_x < 0 ? - 0 : (client->pos_x >= xres ? xres : client->pos_x); + client->pos_x = clamp_val(client->pos_x, 0, xres); + client->pos_y += packet->dy; - client->pos_y = client->pos_y < 0 ? - 0 : (client->pos_y >= yres ? yres : client->pos_y); + client->pos_y = clamp_val(client->pos_y, 0, yres); p->dx += packet->dx; p->dy += packet->dy; @@ -571,44 +571,50 @@ static int mousedev_open(struct inode *inode, struct file *file) return error; } -static inline int mousedev_limit_delta(int delta, int limit) -{ - return delta > limit ? limit : (delta < -limit ? -limit : delta); -} - -static void mousedev_packet(struct mousedev_client *client, - signed char *ps2_data) +static void mousedev_packet(struct mousedev_client *client, u8 *ps2_data) { struct mousedev_motion *p = &client->packets[client->tail]; + s8 dx, dy, dz; + + dx = clamp_val(p->dx, -127, 127); + p->dx -= dx; + + dy = clamp_val(p->dy, -127, 127); + p->dy -= dy; - ps2_data[0] = 0x08 | - ((p->dx < 0) << 4) | ((p->dy < 0) << 5) | (p->buttons & 0x07); - ps2_data[1] = mousedev_limit_delta(p->dx, 127); - ps2_data[2] = mousedev_limit_delta(p->dy, 127); - p->dx -= ps2_data[1]; - p->dy -= ps2_data[2]; + ps2_data[0] = BIT(3); + ps2_data[0] |= ((dx & BIT(7)) >> 3) | ((dy & BIT(7)) >> 2); + ps2_data[0] |= p->buttons & 0x07; + ps2_data[1] = dx; + ps2_data[2] = dy; switch (client->mode) { case MOUSEDEV_EMUL_EXPS: - ps2_data[3] = mousedev_limit_delta(p->dz, 7); - p->dz -= ps2_data[3]; - ps2_data[3] = (ps2_data[3] & 0x0f) | ((p->buttons & 0x18) << 1); + dz = clamp_val(p->dz, -7, 7); + p->dz -= dz; + + ps2_data[3] = (dz & 0x0f) | ((p->buttons & 0x18) << 1); client->bufsiz = 4; break; case MOUSEDEV_EMUL_IMPS: - ps2_data[0] |= - ((p->buttons & 0x10) >> 3) | ((p->buttons & 0x08) >> 1); - ps2_data[3] = mousedev_limit_delta(p->dz, 127); - p->dz -= ps2_data[3]; + dz = clamp_val(p->dz, -127, 127); + p->dz -= dz; + + ps2_data[0] |= ((p->buttons & 0x10) >> 3) | + ((p->buttons & 0x08) >> 1); + ps2_data[3] = dz; + client->bufsiz = 4; break; case MOUSEDEV_EMUL_PS2: default: - ps2_data[0] |= - ((p->buttons & 0x10) >> 3) | ((p->buttons & 0x08) >> 1); p->dz = 0; + + ps2_data[0] |= ((p->buttons & 0x10) >> 3) | + ((p->buttons & 0x08) >> 1); + client->bufsiz = 3; break; } @@ -714,7 +720,7 @@ static ssize_t mousedev_read(struct file *file, char __user *buffer, { struct mousedev_client *client = file->private_data; struct mousedev *mousedev = client->mousedev; - signed char data[sizeof(client->ps2)]; + u8 data[sizeof(client->ps2)]; int retval = 0; if (!client->ready && !client->buffer && mousedev->exist &&