Thread (27 messages) 27 messages, 3 authors, 2013-03-18
STALE4841d
Revisions (3)
  1. v2 [diff vs current]
  2. v3 current
  3. v4 [diff vs current]

[PATCH V3 17/18] ARM: OMAP2+: Allow GPMC probe to complete even if CS mapping fails

From: Jon Hunter <hidden>
Date: 2013-03-15 15:21:15
Also in: linux-devicetree, linux-omap
Subsystem: arm port, omap general purpose memory controller support, omap power management support, omap2+ support, the rest · Maintainers: Russell King, Roger Quadros, Tony Lindgren, Kevin Hilman, Aaro Koskinen, Andreas Kemnade, Linus Torvalds

When the GPMC driver is probed, we call gpmc_mem_init() to see which
chip-selects have already been configured and enabled by the boot-loader
and allocate space for them. If we fail to allocate space for one
chip-select, then we return failure from the probe and the GPMC driver
will not be available.

Rather than render the GPMC useless for all GPMC devices, if we fail to
allocate space for one chip-select print a warning and disable the
chip-select. This way other GPMC clients can still be used.

There is no downside to this approach, because all GPMC clients need to
request a chip-select before they can use the GPMC and on requesting a
chip-select, if memory has not already been reserved for the chip-select
then it will be.

Signed-off-by: Jon Hunter <redacted>
---
 arch/arm/mach-omap2/gpmc.c |   24 +++++++-----------------
 1 file changed, 7 insertions(+), 17 deletions(-)
diff --git a/arch/arm/mach-omap2/gpmc.c b/arch/arm/mach-omap2/gpmc.c
index 5239d47..ee6601c 100644
--- a/arch/arm/mach-omap2/gpmc.c
+++ b/arch/arm/mach-omap2/gpmc.c
@@ -785,9 +785,9 @@ static void gpmc_mem_exit(void)
 
 }
 
-static int gpmc_mem_init(void)
+static void gpmc_mem_init(void)
 {
-	int cs, rc;
+	int cs;
 
 	/*
 	 * The first 1MB of GPMC address space is typically mapped to
@@ -804,16 +804,12 @@ static int gpmc_mem_init(void)
 		if (!gpmc_cs_mem_enabled(cs))
 			continue;
 		gpmc_cs_get_memconf(cs, &base, &size);
-		rc = gpmc_cs_insert_mem(cs, base, size);
-		if (rc < 0) {
-			while (--cs >= 0)
-				if (gpmc_cs_mem_enabled(cs))
-					gpmc_cs_delete_mem(cs);
-			return rc;
+		if (gpmc_cs_insert_mem(cs, base, size)) {
+			pr_warn("%s: disabling cs %d mapped at 0x%x-0x%x\n",
+				__func__, cs, base, base + size);
+			gpmc_cs_disable_mem(cs);
 		}
 	}
-
-	return 0;
 }
 
 static u32 gpmc_round_ps_to_sync_clk(u32 time_ps, u32 sync_clk)
@@ -1620,13 +1616,7 @@ static int gpmc_probe(struct platform_device *pdev)
 	dev_info(gpmc_dev, "GPMC revision %d.%d\n", GPMC_REVISION_MAJOR(l),
 		 GPMC_REVISION_MINOR(l));
 
-	rc = gpmc_mem_init();
-	if (rc < 0) {
-		clk_disable_unprepare(gpmc_l3_clk);
-		clk_put(gpmc_l3_clk);
-		dev_err(gpmc_dev, "failed to reserve memory\n");
-		return rc;
-	}
+	gpmc_mem_init();
 
 	if (gpmc_setup_irq() < 0)
 		dev_warn(gpmc_dev, "gpmc_setup_irq failed\n");
-- 
1.7.10.4
Keyboard shortcuts
hback out one level
jnext message in thread
kprevious message in thread
ldrill in
Escclose help / fold thread tree
?toggle this help