Merge branch 'for-2.6.25' of git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc

* 'for-2.6.25' of git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc:
  [POWERPC] Add arch-specific walk_memory_remove() for 64-bit powerpc
  [POWERPC] Enable hotplug memory remove for 64-bit powerpc
  [POWERPC] Add remove_memory() for 64-bit powerpc
  [POWERPC] Make cell IOMMU fixed mapping printk more useful
  [POWERPC] Fix potential cell IOMMU bug when switching back to default DMA ops
  [POWERPC] Don't enable cell IOMMU fixed mapping if there are no dma-ranges
  [POWERPC] Fix cell IOMMU null pointer explosion on old firmwares
  [POWERPC] spufs: Fix timing dependent false return from spufs_run_spu
  [POWERPC] spufs: No need to have a runnable SPU for libassist update
  [POWERPC] spufs: Update SPU_Status[CISHP] in backing runcntl write
  [POWERPC] spufs: Fix state_mutex leaks
  [POWERPC] Disable G5 NAP mode during SMU commands on U3

1 files changed, 24 insertions, 1 deletions

diff --git a/drivers/macintosh/smu.c b/drivers/macintosh/smu.c
index 8ba4938..77ad192 100644
--- a/drivers/macintosh/smu.c
+++ b/drivers/macintosh/smu.c
@@ -85,6 +85,7 @@ struct smu_device {
 	u32			cmd_buf_abs;	/* command buffer absolute */
 	struct list_head	cmd_list;
 	struct smu_cmd		*cmd_cur;	/* pending command */
+	int			broken_nap;
 	struct list_head	cmd_i2c_list;
 	struct smu_i2c_cmd	*cmd_i2c_cur;	/* pending i2c command */
 	struct timer_list	i2c_timer;
@@ -135,6 +136,19 @@ static void smu_start_cmd(void)
 	fend = faddr + smu->cmd_buf->length + 2;
 	flush_inval_dcache_range(faddr, fend);
 
+
+	/* We also disable NAP mode for the duration of the command
+	 * on U3 based machines.
+	 * This is slightly racy as it can be written back to 1 by a sysctl
+	 * but that never happens in practice. There seem to be an issue with
+	 * U3 based machines such as the iMac G5 where napping for the
+	 * whole duration of the command prevents the SMU from fetching it
+	 * from memory. This might be related to the strange i2c based
+	 * mechanism the SMU uses to access memory.
+	 */
+	if (smu->broken_nap)
+		powersave_nap = 0;
+
 	/* This isn't exactly a DMA mapping here, I suspect
 	 * the SMU is actually communicating with us via i2c to the
 	 * northbridge or the CPU to access RAM.
@@ -211,6 +225,10 @@ static irqreturn_t smu_db_intr(int irq, void *arg)
 	misc = cmd->misc;
 	mb();
 	cmd->status = rc;
+
+	/* Re-enable NAP mode */
+	if (smu->broken_nap)
+		powersave_nap = 1;
  bail:
 	/* Start next command if any */
 	smu_start_cmd();
@@ -461,7 +479,7 @@ int __init smu_init (void)
         if (np == NULL)
 		return -ENODEV;
 
-	printk(KERN_INFO "SMU driver %s %s\n", VERSION, AUTHOR);
+	printk(KERN_INFO "SMU: Driver %s %s\n", VERSION, AUTHOR);
 
 	if (smu_cmdbuf_abs == 0) {
 		printk(KERN_ERR "SMU: Command buffer not allocated !\n");
@@ -533,6 +551,11 @@ int __init smu_init (void)
 		goto fail;
 	}
 
+	/* U3 has an issue with NAP mode when issuing SMU commands */
+	smu->broken_nap = pmac_get_uninorth_variant() < 4;
+	if (smu->broken_nap)
+		printk(KERN_INFO "SMU: using NAP mode workaround\n");
+
 	sys_ctrler = SYS_CTRLER_SMU;
 	return 0;