Coverity: dc_link_setup_psr(): Integer handling issues

Coverity: dc_link_setup_psr(): Integer handling issues

[coverity-bot]

Hello!

This is an experimental automated report about issues detected by Coverity
from a scan of next-20191031 as part of the linux-next weekly scan project:
https://scan.coverity.com/projects/linux-next-weekly-scan

You're getting this email because you were associated with the identified
lines of code (noted below) that were touched by recent commits:

e0d08a40a63b ("drm/amd/display: Add debugfs entry for reading psr state")

Coverity reported the following:

*** CID 1487399:  Integer handling issues  (OVERFLOW_BEFORE_WIDEN)
/drivers/gpu/drm/amd/display/dc/core/dc_link.c: 2559 in dc_link_setup_psr()
2553     	psr_context->phyType = PHY_TYPE_UNIPHY;
2554     	/*PhyId is associated with the transmitter id*/
2555     	psr_context->smuPhyId =
2556     		transmitter_to_phy_id(link->link_enc->transmitter);
2557
2558     	psr_context->crtcTimingVerticalTotal = stream->timing.v_total;
vvv     CID 1487399:  Integer handling issues  (OVERFLOW_BEFORE_WIDEN)
vvv     Potentially overflowing expression "stream->timing.pix_clk_100hz * 100U" with type "unsigned int" (32 bits, unsigned) is evaluated using 32-bit arithmetic, and then used in a context that expects an expression of type "u64" (64 bits, unsigned).
2559     	psr_context->vsyncRateHz = div64_u64(div64_u64((stream->
2560     					timing.pix_clk_100hz * 100),
2561     					stream->timing.v_total),
2562     					stream->timing.h_total);
2563
2564     	psr_context->psrSupportedDisplayConfig = true;

If this is a false positive, please let us know so we can mark it as
such, or teach the Coverity rules to be smarter. If not, please make
sure fixes get into linux-next. :) For patches fixing this, please
include these lines (but double-check the "Fixes" first):

Reported-by: coverity-bot <keescook+coverity-bot@chromium.org>
Addresses-Coverity-ID: 1487399 ("Integer handling issues")
Fixes: e0d08a40a63b ("drm/amd/display: Add debugfs entry for reading psr state")


Thanks for your attention!

-- 
Coverity-bot