Merge tag 'omap-fixes-against-v3.17-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/tmlind/linux-omap into fixes

Merge "omap fixes against v3.17-rc3" from Tony Lindgren:

Few fixes for omaps mostly for various devices to get them working
properly on the new am437x and dra7 hardware for several devices
such as I2C, NAND, DDR3 and USB. There's also a clock fix for omap3.

And also included are two minor cosmetic fixes that are not
stictly fixes for the new hardware support added recently to
downgrade a GPMC warning into a debug statement, and fix the
confusing comments for dra7-evm spi1 mux.

Note that these are all .dts changes except for a GPMC change.

* tag 'omap-fixes-against-v3.17-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/tmlind/linux-omap: (255 commits)
  ARM: dts: dra7-evm: Add vtt regulator support
  ARM: dts: dra7-evm: Fix spi1 mux documentation
  ARM: dts: am43x-epos-evm: Disable QSPI to prevent conflict with GPMC-NAND
  ARM: OMAP2+: gpmc: Don't complain if wait pin is used without r/w monitoring
  ARM: dts: am43xx-epos-evm: Don't use read/write wait monitoring
  ARM: dts: am437x-gp-evm: Don't use read/write wait monitoring
  ARM: dts: am437x-gp-evm: Use BCH16 ECC scheme instead of BCH8
  ARM: dts: am43x-epos-evm: Use BCH16 ECC scheme instead of BCH8
  ARM: dts: am4372: fix USB regs size
  ARM: dts: am437x-gp: switch i2c0 to 100KHz
  ARM: dts: dra7-evm: Fix 8th NAND partition's name
  ARM: dts: dra7-evm: Fix i2c3 pinmux and frequency
  Linux 3.17-rc3
  ...

Signed-off-by: Kevin Hilman <khilman@linaro.org>

3 files changed, 30 insertions, 8 deletions

diff --git a/kernel/kexec.c b/kernel/kexec.c
index 0b49a0a58102..2bee072268d9 100644
--- a/kernel/kexec.c
+++ b/kernel/kexec.c
@@ -64,7 +64,9 @@ bool kexec_in_progress = false;
 char __weak kexec_purgatory[0];
 size_t __weak kexec_purgatory_size = 0;
 
+#ifdef CONFIG_KEXEC_FILE
 static int kexec_calculate_store_digests(struct kimage *image);
+#endif
 
 /* Location of the reserved area for the crash kernel */
 struct resource crashk_res = {
@@ -341,6 +343,7 @@ out_free_image:
         return ret;
 }
 
+#ifdef CONFIG_KEXEC_FILE
 static int copy_file_from_fd(int fd, void **buf, unsigned long *buf_len)
 {
         struct fd f = fdget(fd);
@@ -612,6 +615,9 @@ out_free_image:
         kfree(image);
         return ret;
 }
+#else /* CONFIG_KEXEC_FILE */
+static inline void kimage_file_post_load_cleanup(struct kimage *image) { }
+#endif /* CONFIG_KEXEC_FILE */
 
 static int kimage_is_destination_range(struct kimage *image,
                                         unsigned long start,
@@ -1375,6 +1381,7 @@ COMPAT_SYSCALL_DEFINE4(kexec_load, compat_ulong_t, entry,
 }
 #endif
 
+#ifdef CONFIG_KEXEC_FILE
 SYSCALL_DEFINE5(kexec_file_load, int, kernel_fd, int, initrd_fd,
                 unsigned long, cmdline_len, const char __user *, cmdline_ptr,
                 unsigned long, flags)
@@ -1451,6 +1458,8 @@ out:
         return ret;
 }
 
+#endif /* CONFIG_KEXEC_FILE */
+
 void crash_kexec(struct pt_regs *regs)
 {
         /* Take the kexec_mutex here to prevent sys_kexec_load
@@ -2006,6 +2015,7 @@ static int __init crash_save_vmcoreinfo_init(void)
 
 subsys_initcall(crash_save_vmcoreinfo_init);
 
+#ifdef CONFIG_KEXEC_FILE
 static int __kexec_add_segment(struct kimage *image, char *buf,
                                unsigned long bufsz, unsigned long mem,
                                unsigned long memsz)
@@ -2682,6 +2692,7 @@ int kexec_purgatory_get_set_symbol(struct kimage *image, const char *name,
 
         return 0;
 }
+#endif /* CONFIG_KEXEC_FILE */
 
 /*
  * Move into place and start executing a preloaded standalone
diff --git a/kernel/resource.c b/kernel/resource.c
index da14b8d09296..60c5a3856ab7 100644
--- a/kernel/resource.c
+++ b/kernel/resource.c
@@ -351,15 +351,12 @@ static int find_next_iomem_res(struct resource *res, char *name,
         end = res->end;
         BUG_ON(start >= end);
 
-        read_lock(&resource_lock);
-
-        if (first_level_children_only) {
-                p = iomem_resource.child;
+        if (first_level_children_only)
                 sibling_only = true;
-        } else
-                p = &iomem_resource;
 
-        while ((p = next_resource(p, sibling_only))) {
+        read_lock(&resource_lock);
+
+        for (p = iomem_resource.child; p; p = next_resource(p, sibling_only)) {
                 if (p->flags != res->flags)
                         continue;
                 if (name && strcmp(p->name, name))
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index afb04b9b818a..b38fb2b9e237 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -626,8 +626,22 @@ int ring_buffer_poll_wait(struct ring_buffer *buffer, int cpu,
                 work = &cpu_buffer->irq_work;
         }
 
-        work->waiters_pending = true;
         poll_wait(filp, &work->waiters, poll_table);
+        work->waiters_pending = true;
+        /*
+         * There's a tight race between setting the waiters_pending and
+         * checking if the ring buffer is empty.  Once the waiters_pending bit
+         * is set, the next event will wake the task up, but we can get stuck
+         * if there's only a single event in.
+         *
+         * FIXME: Ideally, we need a memory barrier on the writer side as well,
+         * but adding a memory barrier to all events will cause too much of a
+         * performance hit in the fast path.  We only need a memory barrier when
+         * the buffer goes from empty to having content.  But as this race is
+         * extremely small, and it's not a problem if another event comes in, we
+         * will fix it later.
+         */
+        smp_mb();
 
         if ((cpu == RING_BUFFER_ALL_CPUS && !ring_buffer_empty(buffer)) ||
             (cpu != RING_BUFFER_ALL_CPUS && !ring_buffer_empty_cpu(buffer, cpu)))