[PATCH 4.9 21/31] MIPS: IRQ Stack: Fix erroneous jal to plat_irq_dispatch

[Greg Kroah-Hartman]

4.9-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Matt Redfearn <matt.redfearn@xxxxxxxxxx>

commit c25f8064c1d5731a2ce5664def890140dcdd3e5c upstream.

Commit dda45f701c9d ("MIPS: Switch to the irq_stack in interrupts")
changed both the normal and vectored interrupt handlers. Unfortunately
the vectored version, "except_vec_vi_handler", was incorrectly modified
to unconditionally jal to plat_irq_dispatch, rather than doing a jalr to
the vectored handler that has been set up. This is ok for many platforms
which set the vectored handler to plat_irq_dispatch anyway, but will
cause problems with platforms that use other handlers.

Fixes: dda45f701c9d ("MIPS: Switch to the irq_stack in interrupts")
Signed-off-by: Matt Redfearn <matt.redfearn@xxxxxxxxxx>
Cc: Ralf Baechle <ralf@xxxxxxxxxxxxxx>
Cc: Paul Burton <paul.burton@xxxxxxxxxx>
Cc: linux-mips@xxxxxxxxxxxxxx
Patchwork: https://patchwork.linux-mips.org/patch/15110/
Signed-off-by: James Hogan <james.hogan@xxxxxxxxxx>
Signed-off-by: Amit Pundir <amit.pundir@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 arch/mips/kernel/genex.S |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/arch/mips/kernel/genex.S
+++ b/arch/mips/kernel/genex.S
@@ -329,7 +329,7 @@ NESTED(except_vec_vi_handler, 0, sp)
 	PTR_ADD sp, t0, t1
 
 2:
-	jal	plat_irq_dispatch
+	jalr	v0
 
 	/* Restore sp */
 	move	sp, s1