| Message ID | 20200527071150.3381228-7-natechancellor@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | media: atomisp: Address several clang warnings | expand |
diff --git a/drivers/staging/media/atomisp/pci/isp/kernels/xnr/xnr_3.0/ia_css_xnr3.host.c b/drivers/staging/media/atomisp/pci/isp/kernels/xnr/xnr_3.0/ia_css_xnr3.host.c index a9db6366d20b..629f07faf20a 100644 --- a/drivers/staging/media/atomisp/pci/isp/kernels/xnr/xnr_3.0/ia_css_xnr3.host.c +++ b/drivers/staging/media/atomisp/pci/isp/kernels/xnr/xnr_3.0/ia_css_xnr3.host.c @@ -126,7 +126,7 @@ compute_blending(int strength) * exactly as s0.11 fixed point, but -1.0 can. */ isp_strength = -(((strength * isp_scale) + offset) / host_scale); - return MAX(MIN(isp_strength, 0), -XNR_BLENDING_SCALE_FACTOR); + return MAX(MIN(isp_strength, 0), -isp_scale); } void
Clang warns: drivers/staging/media/atomisp/pci/isp/kernels/xnr/xnr_3.0/ia_css_xnr3.host.c:129:35: warning: implicit conversion from 'unsigned long' to 'int32_t' (aka 'int') changes value from 18446744073709543424 to -8192 [-Wconstant-conversion] return MAX(MIN(isp_strength, 0), -XNR_BLENDING_SCALE_FACTOR); ~~~~~~ ~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~ XNR_BLENDING_SCALE_FACTOR is BIT(13), or 8192, which will easily fit into a signed 32-bit integer. However, it is an unsigned long, which means that negating it is the same as subtracting that value from ULONG_MAX + 1, which causes it to be larger than a signed 32-bit integer so it gets implicitly converted. We can avoid this by using the variable isp_scale, which holds the value of XNR_BLENDING_SCALE_FACTOR already, where the implicit conversion from unsigned long to s32 already happened. If that were to ever overflow, clang would warn: https://godbolt.org/z/EeSxLG Link: https://github.com/ClangBuiltLinux/linux/issues/1036 Signed-off-by: Nathan Chancellor <natechancellor@gmail.com> --- .../atomisp/pci/isp/kernels/xnr/xnr_3.0/ia_css_xnr3.host.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)