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 <nick.desaulniers@xxxxxxxxx>
---
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
--
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