| Message ID | 20180815163852.GA4910@embeddedor.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | iio: accel: cros_ec_accel_legacy: Mark expected switch fall-throughs | expand |
Hi, On Wed, Aug 15, 2018 at 11:38:52AM -0500, Gustavo A. R. Silva wrote: > In preparation to enabling -Wimplicit-fallthrough, mark switch cases > where we are expecting to fall through. > > Addresses-Coverity-ID: 1462408 ("Missing break in switch") > Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com> > --- > drivers/iio/accel/cros_ec_accel_legacy.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/drivers/iio/accel/cros_ec_accel_legacy.c b/drivers/iio/accel/cros_ec_accel_legacy.c > index 063e89e..d609654 100644 > --- a/drivers/iio/accel/cros_ec_accel_legacy.c > +++ b/drivers/iio/accel/cros_ec_accel_legacy.c > @@ -385,8 +385,10 @@ static int cros_ec_accel_legacy_probe(struct platform_device *pdev) > switch (i) { > case X: > ec_accel_channels[X].scan_index = Y; > + /* fall through */ > case Y: > ec_accel_channels[Y].scan_index = X; > + /* fall through */ > case Z: > ec_accel_channels[Z].scan_index = Z; > } Hum, I'm not sure we are supposed to fall through here, even if it does not hurt to do so. I even think we can remove the switch and put that outside the for-loop, e.g: ec_accel_channels[X].scan_index = Y; ec_accel_channels[Y].scan_index = X; ec_accel_channels[Z].scan_index = Z; for (i = X ; i < MAX_AXIS; i++) { if (state->sensor_num == MOTIONSENSE_LOC_LID && i != Y) state->sign[i] = -1; else state->sign[i] = 1; } Best regards, Marcus Folkesson > -- > 2.7.4 >
Hi Marcus, On 8/15/18 12:27 PM, Marcus Folkesson wrote: > Hi, > > On Wed, Aug 15, 2018 at 11:38:52AM -0500, Gustavo A. R. Silva wrote: >> In preparation to enabling -Wimplicit-fallthrough, mark switch cases >> where we are expecting to fall through. >> >> Addresses-Coverity-ID: 1462408 ("Missing break in switch") >> Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com> >> --- >> drivers/iio/accel/cros_ec_accel_legacy.c | 2 ++ >> 1 file changed, 2 insertions(+) >> >> diff --git a/drivers/iio/accel/cros_ec_accel_legacy.c b/drivers/iio/accel/cros_ec_accel_legacy.c >> index 063e89e..d609654 100644 >> --- a/drivers/iio/accel/cros_ec_accel_legacy.c >> +++ b/drivers/iio/accel/cros_ec_accel_legacy.c >> @@ -385,8 +385,10 @@ static int cros_ec_accel_legacy_probe(struct platform_device *pdev) >> switch (i) { >> case X: >> ec_accel_channels[X].scan_index = Y; >> + /* fall through */ >> case Y: >> ec_accel_channels[Y].scan_index = X; >> + /* fall through */ >> case Z: >> ec_accel_channels[Z].scan_index = Z; >> } > > Hum, I'm not sure we are supposed to fall through here, even if it does > not hurt to do so. Yeah. You're right. It doesn't hurt but is actually redundant. I think the original intention was to break instead of falling through. > I even think we can remove the switch and put that outside the for-loop, > e.g: > > ec_accel_channels[X].scan_index = Y; > ec_accel_channels[Y].scan_index = X; > ec_accel_channels[Z].scan_index = Z; > > for (i = X ; i < MAX_AXIS; i++) { > if (state->sensor_num == MOTIONSENSE_LOC_LID && i != Y) > state->sign[i] = -1; > else > state->sign[i] = 1; > } > I like this, but the code clearly depends on MAX_AXIS. So, if MAX_AXIS will be always 3, then the change you suggest is just fine. Otherwise, it seems that adding a break to each case is the right way to go. What do you think? Thanks for the feedback. -- Gustavo
Hi Gutavo, Sorry for the delay. On Wed, Aug 15, 2018 at 12:50:10PM -0500, Gustavo A. R. Silva wrote: > Hi Marcus, > > On 8/15/18 12:27 PM, Marcus Folkesson wrote: > > Hi, > > > > On Wed, Aug 15, 2018 at 11:38:52AM -0500, Gustavo A. R. Silva wrote: > >> In preparation to enabling -Wimplicit-fallthrough, mark switch cases > >> where we are expecting to fall through. > >> > >> Addresses-Coverity-ID: 1462408 ("Missing break in switch") > >> Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com> > >> --- > >> drivers/iio/accel/cros_ec_accel_legacy.c | 2 ++ > >> 1 file changed, 2 insertions(+) > >> > >> diff --git a/drivers/iio/accel/cros_ec_accel_legacy.c b/drivers/iio/accel/cros_ec_accel_legacy.c > >> index 063e89e..d609654 100644 > >> --- a/drivers/iio/accel/cros_ec_accel_legacy.c > >> +++ b/drivers/iio/accel/cros_ec_accel_legacy.c > >> @@ -385,8 +385,10 @@ static int cros_ec_accel_legacy_probe(struct platform_device *pdev) > >> switch (i) { > >> case X: > >> ec_accel_channels[X].scan_index = Y; > >> + /* fall through */ > >> case Y: > >> ec_accel_channels[Y].scan_index = X; > >> + /* fall through */ > >> case Z: > >> ec_accel_channels[Z].scan_index = Z; > >> } > > > > Hum, I'm not sure we are supposed to fall through here, even if it does > > not hurt to do so. > > Yeah. You're right. It doesn't hurt but is actually redundant. I think > the original intention was to break instead of falling through. > > > I even think we can remove the switch and put that outside the for-loop, > > e.g: > > > > ec_accel_channels[X].scan_index = Y; > > ec_accel_channels[Y].scan_index = X; > > ec_accel_channels[Z].scan_index = Z; > > > > for (i = X ; i < MAX_AXIS; i++) { > > if (state->sensor_num == MOTIONSENSE_LOC_LID && i != Y) > > state->sign[i] = -1; > > else > > state->sign[i] = 1; > > } > > > > I like this, but the code clearly depends on MAX_AXIS. So, if MAX_AXIS > will be always 3, then the change you suggest is just fine. Otherwise, > it seems that adding a break to each case is the right way to go. > > What do you think? Well, I guess it is a matter of taste after all. I don't think the number of axis will change, but just put the break in place is good enough. Anyway, If we choose to not use the switch, I think we should remove the for-loop as well, eg: ec_accel_channels[X].scan_index = Y; ec_accel_channels[Y].scan_index = X; ec_accel_channels[Z].scan_index = Z; if (state->sensor_num == MOTIONSENSE_LOC_LID) { state->sign[X] = -1; state->sign[Y] = 1; state->sign[Z] = -1; } else { state->sign[X] = 1; state->sign[Y] = 1; state->sign[Z] = 1; } But someone else may like to give their point of view on this change. > > Thanks for the feedback. > -- > Gustavo Best regards Marcus Folkesson
On Sat, 18 Aug 2018 17:34:40 +0200 Marcus Folkesson <marcus.folkesson@gmail.com> wrote: > Hi Gutavo, > > Sorry for the delay. > > On Wed, Aug 15, 2018 at 12:50:10PM -0500, Gustavo A. R. Silva wrote: > > Hi Marcus, > > > > On 8/15/18 12:27 PM, Marcus Folkesson wrote: > > > Hi, > > > > > > On Wed, Aug 15, 2018 at 11:38:52AM -0500, Gustavo A. R. Silva wrote: > > >> In preparation to enabling -Wimplicit-fallthrough, mark switch cases > > >> where we are expecting to fall through. > > >> > > >> Addresses-Coverity-ID: 1462408 ("Missing break in switch") > > >> Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com> > > >> --- > > >> drivers/iio/accel/cros_ec_accel_legacy.c | 2 ++ > > >> 1 file changed, 2 insertions(+) > > >> > > >> diff --git a/drivers/iio/accel/cros_ec_accel_legacy.c b/drivers/iio/accel/cros_ec_accel_legacy.c > > >> index 063e89e..d609654 100644 > > >> --- a/drivers/iio/accel/cros_ec_accel_legacy.c > > >> +++ b/drivers/iio/accel/cros_ec_accel_legacy.c > > >> @@ -385,8 +385,10 @@ static int cros_ec_accel_legacy_probe(struct platform_device *pdev) > > >> switch (i) { > > >> case X: > > >> ec_accel_channels[X].scan_index = Y; > > >> + /* fall through */ > > >> case Y: > > >> ec_accel_channels[Y].scan_index = X; > > >> + /* fall through */ > > >> case Z: > > >> ec_accel_channels[Z].scan_index = Z; > > >> } > > > > > > Hum, I'm not sure we are supposed to fall through here, even if it does > > > not hurt to do so. > > > > Yeah. You're right. It doesn't hurt but is actually redundant. I think > > the original intention was to break instead of falling through. > > > > > I even think we can remove the switch and put that outside the for-loop, > > > e.g: > > > > > > ec_accel_channels[X].scan_index = Y; > > > ec_accel_channels[Y].scan_index = X; > > > ec_accel_channels[Z].scan_index = Z; > > > > > > for (i = X ; i < MAX_AXIS; i++) { > > > if (state->sensor_num == MOTIONSENSE_LOC_LID && i != Y) > > > state->sign[i] = -1; > > > else > > > state->sign[i] = 1; > > > } > > > > > > > I like this, but the code clearly depends on MAX_AXIS. So, if MAX_AXIS > > will be always 3, then the change you suggest is just fine. Otherwise, > > it seems that adding a break to each case is the right way to go. > > > > What do you think? > > Well, I guess it is a matter of taste after all. > I don't think the number of axis will change, but just put the break in > place is good enough. > > Anyway, If we choose to not use the switch, I think we should remove the > for-loop as well, eg: > > ec_accel_channels[X].scan_index = Y; > ec_accel_channels[Y].scan_index = X; > ec_accel_channels[Z].scan_index = Z; > > if (state->sensor_num == MOTIONSENSE_LOC_LID) { > state->sign[X] = -1; > state->sign[Y] = 1; > state->sign[Z] = -1; > } else { > state->sign[X] = 1; > state->sign[Y] = 1; > state->sign[Z] = 1; > } > > But someone else may like to give their point of view on this change. Looks like the right tidy up to me. The original code was 'novel' :) Jonathan > > > > > Thanks for the feedback. > > -- > > Gustavo > > Best regards > Marcus Folkesson
diff --git a/drivers/iio/accel/cros_ec_accel_legacy.c b/drivers/iio/accel/cros_ec_accel_legacy.c index 063e89e..d609654 100644 --- a/drivers/iio/accel/cros_ec_accel_legacy.c +++ b/drivers/iio/accel/cros_ec_accel_legacy.c @@ -385,8 +385,10 @@ static int cros_ec_accel_legacy_probe(struct platform_device *pdev) switch (i) { case X: ec_accel_channels[X].scan_index = Y; + /* fall through */ case Y: ec_accel_channels[Y].scan_index = X; + /* fall through */ case Z: ec_accel_channels[Z].scan_index = Z; }
In preparation to enabling -Wimplicit-fallthrough, mark switch cases where we are expecting to fall through. Addresses-Coverity-ID: 1462408 ("Missing break in switch") Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com> --- drivers/iio/accel/cros_ec_accel_legacy.c | 2 ++ 1 file changed, 2 insertions(+)