@@ -2752,11 +2752,9 @@ func_return get_new_page
#ifdef CONFIG_MAC
L(scc_initable_mac):
- .byte 9,12 /* Reset */
.byte 4,0x44 /* x16, 1 stopbit, no parity */
.byte 3,0xc0 /* receiver: 8 bpc */
.byte 5,0xe2 /* transmitter: 8 bpc, assert dtr/rts */
- .byte 9,0 /* no interrupts */
.byte 10,0 /* NRZ */
.byte 11,0x50 /* use baud rate generator */
.byte 12,1,13,0 /* 38400 baud */
@@ -2899,6 +2897,7 @@ func_start serial_init,%d0/%d1/%a0/%a1
is_not_mac(L(serial_init_not_mac))
#ifdef SERIAL_DEBUG
+
/* You may define either or both of these. */
#define MAC_USE_SCC_A /* Modem port */
#define MAC_USE_SCC_B /* Printer port */
@@ -2908,9 +2907,21 @@ func_start serial_init,%d0/%d1/%a0/%a1
#define mac_scc_cha_b_data_offset 0x4
#define mac_scc_cha_a_data_offset 0x6
+#if defined(MAC_USE_SCC_A) || defined(MAC_USE_SCC_B)
+ movel %pc@(L(mac_sccbase)),%a0
+ /* Reset SCC device */
+ 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 */
+ /* 5 / 3.6864 MHz = approx. 1.36 us = 68 / 50 MHz */
+ movel #35,%d0
+5:
+ subq #1,%d0
+ jne 5b
+#endif
+
#ifdef MAC_USE_SCC_A
/* Initialize channel A */
- movel %pc@(L(mac_sccbase)),%a0
lea %pc@(L(scc_initable_mac)),%a1
5: moveb %a1@+,%d0
jmi 6f
@@ -2922,9 +2933,6 @@ func_start serial_init,%d0/%d1/%a0/%a1
#ifdef MAC_USE_SCC_B
/* Initialize channel B */
-#ifndef MAC_USE_SCC_A /* Load mac_sccbase only if needed */
- movel %pc@(L(mac_sccbase)),%a0
-#endif /* MAC_USE_SCC_A */
lea %pc@(L(scc_initable_mac)),%a1
7: moveb %a1@+,%d0
jmi 8f
@@ -2933,6 +2941,7 @@ func_start serial_init,%d0/%d1/%a0/%a1
jra 7b
8:
#endif /* MAC_USE_SCC_B */
+
#endif /* SERIAL_DEBUG */
jra L(serial_init_done)
@@ -3006,17 +3015,17 @@ func_start serial_putc,%d0/%d1/%a0/%a1
#ifdef SERIAL_DEBUG
-#ifdef MAC_USE_SCC_A
+#if defined(MAC_USE_SCC_A) || defined(MAC_USE_SCC_B)
movel %pc@(L(mac_sccbase)),%a1
+#endif
+
+#ifdef MAC_USE_SCC_A
3: btst #2,%a1@(mac_scc_cha_a_ctrl_offset)
jeq 3b
moveb %d0,%a1@(mac_scc_cha_a_data_offset)
#endif /* MAC_USE_SCC_A */
#ifdef MAC_USE_SCC_B
-#ifndef MAC_USE_SCC_A /* Load mac_sccbase only if needed */
- movel %pc@(L(mac_sccbase)),%a1
-#endif /* MAC_USE_SCC_A */
4: btst #2,%a1@(mac_scc_cha_b_ctrl_offset)
jeq 4b
moveb %d0,%a1@(mac_scc_cha_b_data_offset)
This is a note to let you know that I have just added a patch titled m68k/mac: Fix unexpected interrupt with CONFIG_EARLY_PRINTK to the linux-3.8.y-queue branch of the 3.8.y.z extended stable tree which can be found at: http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.8.y-queue This patch is scheduled to be released in version 3.8.13.2. If you, or anyone else, feels it should not be added to this tree, please reply to this email. For more information about the 3.8.y.z tree, see https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable Thanks. -Kamal ------ From 654ad7b833638438c698582cfb0f0b5eb46736ee Mon Sep 17 00:00:00 2001 From: Finn Thain <fthain@telegraphics.com.au> Date: Wed, 29 May 2013 12:37:17 +1000 Subject: m68k/mac: Fix unexpected interrupt with CONFIG_EARLY_PRINTK commit df66834a43c461de2565c45d815288ba1c0def37 upstream. The present code does not wait for the SCC to finish resetting itself before trying to initialise the device. The result is that the SCC interrupt sources become enabled (if they weren't already). This leads to an early boot crash (unexpected interrupt) given CONFIG_EARLY_PRINTK. Fix this by adding a delay. A successful reset disables the interrupt sources. Also, after the reset for channel A setup, the SCC then gets a second reset for channel B setup which leaves channel A uninitialised again. Fix this by performing the reset only once. Signed-off-by: Finn Thain <fthain@telegraphics.com.au> Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Kamal Mostafa <kamal@canonical.com> --- arch/m68k/kernel/head.S | 29 +++++++++++++++++++---------- 1 file changed, 19 insertions(+), 10 deletions(-) -- 1.8.1.2