[PATCH v4] Input: mousedev - fix implicit conversion warning
From: Nick Desaulniers <hidden>
Date: 2017-05-30 05:42:11
Also in:
lkml
Subsystem:
input (keyboard, mouse, joystick, touchscreen) drivers, the rest · Maintainers:
Dmitry Torokhov, Linus Torvalds
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 far as I can tell, from
http://www.computer-engineering.org/ps2mouse/
Under "Command Set" > "0xE9 (Status Request)"
the value 200 is a valid sample rate. Using unsigned char [], rather than
signed char [], for client->ps2 silences this warning.
Also moves some reused logic into a helper function.
Signed-off-by: Nick Desaulniers <redacted>
---
What's new in v4:
* replace mousedev_limit_delta() with update_clamped() that also updates
the ps2_data and delta values. The use of the temporary val should
avoid integral conversion and promotion issues.
drivers/input/mousedev.c | 23 +++++++++++------------
1 file changed, 11 insertions(+), 12 deletions(-)
diff --git a/drivers/input/mousedev.c b/drivers/input/mousedev.c
index 0e0ff84088fd..e645b8c6f2cb 100644
--- a/drivers/input/mousedev.c
+++ b/drivers/input/mousedev.c@@ -103,7 +103,7 @@ struct mousedev_client { spinlock_t packet_lock; int pos_x, pos_y; - signed char ps2[6]; + unsigned char ps2[6]; unsigned char ready, buffer, bufsiz; unsigned char imexseq, impsseq; enum mousedev_emul mode;
@@ -571,27 +571,27 @@ static int mousedev_open(struct inode *inode, struct file *file) return error; } -static inline int mousedev_limit_delta(int delta, int limit) +static inline void +update_clamped(unsigned char *ps2_data, int *delta, int limit) { - return delta > limit ? limit : (delta < -limit ? -limit : delta); + int val = *delta > limit ? limit : (*delta < -limit ? -limit : *delta); + *ps2_data = (unsigned char) val; + *delta -= val; } static void mousedev_packet(struct mousedev_client *client, - signed char *ps2_data) + unsigned char *ps2_data) { struct mousedev_motion *p = &client->packets[client->tail]; 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]; + update_clamped(&ps2_data[1], &p->dx, 127); + update_clamped(&ps2_data[2], &p->dy, 127); switch (client->mode) { case MOUSEDEV_EMUL_EXPS: - ps2_data[3] = mousedev_limit_delta(p->dz, 7); - p->dz -= ps2_data[3]; + update_clamped(&ps2_data[3], &p->dz, 7); ps2_data[3] = (ps2_data[3] & 0x0f) | ((p->buttons & 0x18) << 1); client->bufsiz = 4; break;
@@ -599,8 +599,7 @@ static void mousedev_packet(struct mousedev_client *client, 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]; + update_clamped(&ps2_data[3], &p->dz, 127); client->bufsiz = 4; break;
--
2.11.0