MdeModulePkg/Bus/Pci/UhciDxe: Fix BAD_SHIFT Coverity issue

The function UhciConvertPollRate has a check

    ASSERT (Interval != 0);

but this comes into play only in DEBUG mode. In Release mode, there is
no handling if the Interval parameter value is ZERO. To avoid shifting
by a negative amount later in the code flow in this undesirable case,
it is better to handle it as well by treating it same as if 1 is sent.

REF: https://bugzilla.tianocore.org/show_bug.cgi?id=4211

Cc: Hao A Wu <hao.a.wu@intel.com>
Cc: Ray Ni <ray.ni@intel.com>
Co-authored-by: Veeresh Sangolli <veeresh.sangolli@dellteam.com>
Signed-off-by: Ranbir Singh <Ranbir.Singh3@Dell.com>
Signed-off-by: Ranbir Singh <rsingh@ventanamicro.com>
Reviewed-by: Hao A Wu <hao.a.wu@intel.com>

1 files changed, 9 insertions, 1 deletions

diff --git a/MdeModulePkg/Bus/Pci/UhciDxe/UhciSched.c b/MdeModulePkg/Bus/Pci/UhciDxe/UhciSched.c
index c08f949696..408e7d5ab7 100644
--- a/MdeModulePkg/Bus/Pci/UhciDxe/UhciSched.c
+++ b/MdeModulePkg/Bus/Pci/UhciDxe/UhciSched.c
@@ -197,7 +197,7 @@ UhciDestoryFrameList (
 }

 

 /**

-  Convert the poll rate to the maxium 2^n that is smaller

+  Convert the poll rate to the maximum 2^n that is smaller

   than Interval.

 

   @param  Interval               The poll rate to convert.

@@ -215,6 +215,14 @@ UhciConvertPollRate (
   ASSERT (Interval != 0);

 

   //

+  // To safeguard RELEASE mode wherein ASSERT is effectively not there,

+  // if inadvertently Interval is still 0 here, treat it the same as 1.

+  //

+  if (Interval == 0) {

+    Interval = 1;

+  }

+

+  //

   // Find the index (1 based) of the highest non-zero bit

   //

   BitCount = 0;