Issue while upgrading SQL Server 2012

Question

When I tried to upgrade SQL Server 2008 R2 to SQL Server 2012 everything went well except below issue

How do I fix it? Do I need to uninstall SQL Server 2012 again?

EDIT

Feature:                       Reporting Services - Native
  Status:                        Failed: see logs for details
  Reason for failure:            An error occurred for a dependency of the feature causing the setup process for the feature to fail.
  Next Step:                     The upgrade process for SQL Server failed. Use the following information to resolve the error, and then repair your installation by using this command line: setup /action=repair /instancename=MSSQLSERVER
  Component name:                SQL Server Database Engine Services Instance Features
  Component error code:          0x84BB0001
  Error description:             Service 'SQLSERVERAGENT' stop request failed.
  Error help link:               http://go.microsoft.com/fwlink?LinkId=20476&ProdName=Microsoft+SQL+Server&EvtSrc=setup.rll&EvtID=50000&ProdVer=11.0.2100.60&EvtType=0x2E920AA9%400xD3BEBD98%401211%401&EvtType=0x2E920AA9%400xD3BEBD98%401211%401

  Feature:                       Database Engine Services
  Status:                        Failed: see logs for details
  Reason for failure:            An error occurred during the setup process of the feature.
  Next Step:                     The upgrade process for SQL Server failed. Use the following information to resolve the error, and then repair your installation by using this command line: setup /action=repair /instancename=MSSQLSERVER
  Component name:                SQL Server Database Engine Services Instance Features
  Component error code:          0x84BB0001
  Error description:             Service 'SQLSERVERAGENT' stop request failed.
  Error help link:               http://go.microsoft.com/fwlink?LinkId=20476&ProdName=Microsoft+SQL+Server&EvtSrc=setup.rll&EvtID=50000&ProdVer=11.0.2100.60&EvtType=0x2E920AA9%400xD3BEBD98%401211%401&EvtType=0x2E920AA9%400xD3BEBD98%401211%401

  Feature:                       Full-Text and Semantic Extractions for Search
  Status:                        Failed: see logs for details
  Reason for failure:            An error occurred for a dependency of the feature causing the setup process for the feature to fail.
  Next Step:                     The upgrade process for SQL Server failed. Use the following information to resolve the error, and then repair your installation by using this command line: setup /action=repair /instancename=MSSQLSERVER
  Component name:                SQL Server Database Engine Services Instance Features
  Component error code:          0x84BB0001
  Error description:             Service 'SQLSERVERAGENT' stop request failed.
  Error help link:               http://go.microsoft.com/fwlink?LinkId=20476&ProdName=Microsoft+SQL+Server&EvtSrc=setup.rll&EvtID=50000&ProdVer=11.0.2100.60&EvtType=0x2E920AA9%400xD3BEBD98%401211%401&EvtType=0x2E920AA9%400xD3BEBD98%401211%401

  Feature:                       SQL Server Replication
  Status:                        Failed: see logs for details
  Reason for failure:            An error occurred for a dependency of the feature causing the setup process for the feature to fail.
  Next Step:                     The upgrade process for SQL Server failed. Use the following information to resolve the error, and then repair your installation by using this command line: setup /action=repair /instancename=MSSQLSERVER
  Component name:                SQL Server Database Engine Services Instance Features
  Component error code:          0x84BB0001
  Error description:             Service 'SQLSERVERAGENT' stop request failed.
  Error help link:               http://go.microsoft.com/fwlink?LinkId=20476&ProdName=Microsoft+SQL+Server&EvtSrc=setup.rll&EvtID=50000&ProdVer=11.0.2100.60&EvtType=0x2E920AA9%400xD3BEBD98%401211%401&EvtType=0x2E920AA9%400xD3BEBD98%401211%401

Edit: Error while reparing it

    SQL Server Setup has encountered the following error:

The specified value 'Repair' is invalid. To run in unattended mode, you must specify a valid ACTION. The valid values for ACTION are: '
None
RemovePatch
Uninstall
Install
Upgrade
Patch
Repair
LandingPage
ClusterReport
RunRules
PrepareFailoverCluster
CompleteFailoverCluster
InstallFailoverCluster
RemoveNode
AddNode
EditionUpgrade
Bootstrap
ComponentUpdate
Help
RebuildDatabase
RunDiscovery
PrepareImage
CompleteImage
ConfigureImage'

command I have used

D:/myfolder/setup.exe /q /ACTION=Repair /INSTANCENAME=MSSQLSERVER

After Repair

Answer 1

I'd try to stop it manually (stop SQL Server Agent from the services.msc) and then repair.

Your database engine services upgrade failed. You'll need to repair it by running setup /action=repair /instancename=MSSQLSERVER after fixing the problem that caused it to fail in the first place.