For SCC initialization we cannot assume that the control register is in the correct state to accept a register pointer. So first read from the control register in order to "sync" up.
Signed-off-by: Finn Thain <[email protected]> --- This patch fixes a boot failure (presumably caused by unhandled SCC interrupt) on PowerBook 180 with CONFIG_EARLY_PRINTK and with the bootloader not configured to wake up the serial ports. AFAIK this happens only on PowerBooks. Even with this fix, Penguin still has to wake the serial ports or else they don't function on PowerBooks like this one. diff --git a/arch/m68k/kernel/head.S b/arch/m68k/kernel/head.S --- a/arch/m68k/kernel/head.S +++ b/arch/m68k/kernel/head.S @@ -2909,7 +2909,9 @@ func_start serial_init,%d0/%d1/%a0/%a1 #if defined(MAC_USE_SCC_A) || defined(MAC_USE_SCC_B) movel %pc@(L(mac_sccbase)),%a0 - /* Reset SCC device */ + /* Reset SCC register pointer */ + moveb %a0@(mac_scc_cha_a_ctrl_offset),%d0 + /* Reset SCC device: write register pointer then register value */ moveb #9,%a0@(mac_scc_cha_a_ctrl_offset) moveb #0xc0,%a0@(mac_scc_cha_a_ctrl_offset) /* Wait for 5 PCLK cycles, which is about 68 CPU cycles */ -- To unsubscribe from this list: send the line "unsubscribe linux-m68k" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
