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-rw-r--r--target/linux/generic/patches-3.3/048-spi-Dont-call-prepare-unprepare-transfer-if-not-popu.patch39
1 files changed, 39 insertions, 0 deletions
diff --git a/target/linux/generic/patches-3.3/048-spi-Dont-call-prepare-unprepare-transfer-if-not-popu.patch b/target/linux/generic/patches-3.3/048-spi-Dont-call-prepare-unprepare-transfer-if-not-popu.patch
new file mode 100644
index 000000000..deef32e45
--- /dev/null
+++ b/target/linux/generic/patches-3.3/048-spi-Dont-call-prepare-unprepare-transfer-if-not-popu.patch
@@ -0,0 +1,39 @@
+From 7dfd2bd70228d1f8d468d58cb3d12ecd618479ed Mon Sep 17 00:00:00 2001
+From: Shubhrajyoti D <shubhrajyoti@ti.com>
+Date: Thu, 10 May 2012 19:20:41 +0530
+Subject: [PATCH] spi: Dont call prepare/unprepare transfer if not populated
+
+Currently the prepare/unprepare transfer are called unconditionally.
+The assumption is that every driver using the spi core queue infrastructure
+has to populate the prepare and unprepare functions. This encourages
+drivers to populate empty functions to prevent crashing.
+This patch prevents the call to prepare/unprepare if not populated.
+
+Signed-off-by: Shubhrajyoti D <shubhrajyoti@ti.com>
+Acked-by: Linus Walleij <linus.walleij@linaro.org>
+[grant.likely: fix whitespace defect]
+Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
+---
+ drivers/spi/spi.c | 4 ++--
+ 1 files changed, 2 insertions(+), 2 deletions(-)
+
+--- a/drivers/spi/spi.c
++++ b/drivers/spi/spi.c
+@@ -530,7 +530,7 @@ static void spi_pump_messages(struct kth
+ /* Lock queue and check for queue work */
+ spin_lock_irqsave(&master->queue_lock, flags);
+ if (list_empty(&master->queue) || !master->running) {
+- if (master->busy) {
++ if (master->busy && master->unprepare_transfer_hardware) {
+ ret = master->unprepare_transfer_hardware(master);
+ if (ret) {
+ dev_err(&master->dev,
+@@ -559,7 +559,7 @@ static void spi_pump_messages(struct kth
+ master->busy = true;
+ spin_unlock_irqrestore(&master->queue_lock, flags);
+
+- if (!was_busy) {
++ if (!was_busy && master->prepare_transfer_hardware) {
+ ret = master->prepare_transfer_hardware(master);
+ if (ret) {
+ dev_err(&master->dev,