Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc

* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc: (158 commits)
  powerpc: Fix CHRP PCI config access for indirect_pci
  powerpc/chrp: Fix detection of Python PCI host bridge on IBM CHRPs
  powerpc: Fix 32-bit SMP boot on CHRP
  powerpc: Fix link errors on 32-bit machines using legacy DMA
  powerpc/pci: Improve detection of unassigned bridge resources
  hvc_console: Fix free_irq in spinlocked section
  powerpc: Get USE_STRICT_MM_TYPECHECKS working again
  powerpc: Reflect the used arguments in machine_init() prototype
  powerpc: Fix DMA offset for non-coherent DMA
  powerpc: fix fsl_upm nand driver modular build
  powerpc/83xx: add NAND support for the MPC8360E-RDK boards
  powerpc: FPGA support for GE Fanuc SBC610
  i2c: MPC8349E-mITX Power Management and GPIO expander driver
  powerpc: reserve two DMA channels for audio in MPC8610 HPCD device tree
  powerpc: document the "fsl,ssi-dma-channel" compatible property
  powerpc: disable CHRP and PMAC support in various defconfigs
  OF: add fsl,mcu-mpc8349emitx to the exception list
  powerpc/83xx: add DS1374 RTC support for the MPC837xE-MDS boards
  powerpc: remove support for bootmem-allocated memory for the DIU driver
  powerpc: remove non-dependent load fsl_booke PTE_64BIT
  ...

1 files changed, 18 insertions, 8 deletions

diff --git a/arch/powerpc/platforms/pseries/rtasd.c b/arch/powerpc/platforms/pseries/rtasd.c
index c9ffd8c225f1..f4e55be2eea9 100644
--- a/arch/powerpc/platforms/pseries/rtasd.c
+++ b/arch/powerpc/platforms/pseries/rtasd.c
@@ -295,19 +295,29 @@ static ssize_t rtas_log_read(struct file * file, char __user * buf,
 	if (!tmp)
 		return -ENOMEM;
 
-
 	spin_lock_irqsave(&rtasd_log_lock, s);
 	/* if it's 0, then we know we got the last one (the one in NVRAM) */
-	if (rtas_log_size == 0 && logging_enabled)
-		nvram_clear_error_log();
-	spin_unlock_irqrestore(&rtasd_log_lock, s);
+	while (rtas_log_size == 0) {
+		if (file->f_flags & O_NONBLOCK) {
+			spin_unlock_irqrestore(&rtasd_log_lock, s);
+			error = -EAGAIN;
+			goto out;
+		}
 
+		if (!logging_enabled) {
+			spin_unlock_irqrestore(&rtasd_log_lock, s);
+			error = -ENODATA;
+			goto out;
+		}
+		nvram_clear_error_log();
 
-	error = wait_event_interruptible(rtas_log_wait, rtas_log_size);
-	if (error)
-		goto out;
+		spin_unlock_irqrestore(&rtasd_log_lock, s);
+		error = wait_event_interruptible(rtas_log_wait, rtas_log_size);
+		if (error)
+			goto out;
+		spin_lock_irqsave(&rtasd_log_lock, s);
+	}
 
-	spin_lock_irqsave(&rtasd_log_lock, s);
 	offset = rtas_error_log_buffer_max * (rtas_log_start & LOG_NUMBER_MASK);
 	memcpy(tmp, &rtas_log_buf[offset], count);