diff options
Diffstat (limited to 'cpu/mpc8xx/interrupts.c')
| -rw-r--r-- | cpu/mpc8xx/interrupts.c | 20 |
1 files changed, 15 insertions, 5 deletions
diff --git a/cpu/mpc8xx/interrupts.c b/cpu/mpc8xx/interrupts.c index 558dc09c0..20e7012c3 100644 --- a/cpu/mpc8xx/interrupts.c +++ b/cpu/mpc8xx/interrupts.c @@ -274,11 +274,21 @@ void timer_interrupt_cpu (struct pt_regs *regs) /* Reset Timer Expired and Timers Interrupt Status */ immr->im_clkrstk.cark_plprcrk = KAPWR_KEY; __asm__ ("nop"); -#ifdef CONFIG_MPC866_et_al - immr->im_clkrst.car_plprcr |= PLPRCR_TEXPS; -#else - immr->im_clkrst.car_plprcr |= PLPRCR_TEXPS | PLPRCR_TMIST; -#endif + /* + Clear TEXPS (and TMIST on older chips). SPLSS (on older + chips) is cleared too. + + Bitwise OR is a read-modify-write operation so ALL bits + which are cleared by writing `1' would be cleared by + operations like + + immr->im_clkrst.car_plprcr |= PLPRCR_TEXPS; + + The same can be achieved by simple writing of the PLPRCR + to itself. If a bit value should be preserved, read the + register, ZERO the bit and write, not OR, the result back. + */ + immr->im_clkrst.car_plprcr = immr->im_clkrst.car_plprcr; } /************************************************************************/ |