[PATCH 11/13] FB: sa1100: make GPIO configuration setting safe
From: Russell King - ARM Linux <hidden>
Date: 2012-02-04 09:41:48
Also in:
linux-fbdev
Subsystem:
framebuffer layer, the rest · Maintainers:
Helge Deller, Linus Torvalds
The sa1100fb driver needs to set the GPIO direction and alternate function register according to the panel that we're driving. We've done this in the driver by read-modify-writing the register, which may cause problems with races. Fix this with a minimal change. Signed-off-by: Russell King <redacted> --- drivers/video/sa1100fb.c | 11 +++++++++++ 1 files changed, 11 insertions(+), 0 deletions(-)
diff --git a/drivers/video/sa1100fb.c b/drivers/video/sa1100fb.c
index d1d97ca..b644f0f 100644
--- a/drivers/video/sa1100fb.c
+++ b/drivers/video/sa1100fb.c@@ -761,8 +761,19 @@ static void sa1100fb_setup_gpio(struct sa1100fb_info *fbi) } if (mask) { + unsigned long flags; + + /* + * SA-1100 requires the GPIO direction register set + * appropriately for the alternate function. Hence + * we set it here via bitmask rather than excessive + * fiddling via the GPIO subsystem - and even then + * we'll still have to deal with GAFR. + */ + local_irq_save(flags); GPDR |= mask; GAFR |= mask; + local_irq_restore(flags); } }
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1.7.4.4