ARM: davinci: da850: fix infinite loop in clk_set_rate()

The aemif clock is added twice to the lookup table in da850.c. This
breaks the children list of pll0_sysclk3 as we're using the same list
links in struct clk. When calling clk_set_rate(), we get stuck in
propagate_rate().

Create a separate clock for nand, inheriting the rate of the aemif
clock and retrieve it in the davinci_nand module.

Cc: <stable@vger.kernel.org> # 4.9.x
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Signed-off-by: Sekhar Nori <nsekhar@ti.com>

diff --git a/arch/arm/mach-davinci/da850.c b/arch/arm/mach-davinci/da850.c
index e770c97ea45c28bfc77232bb1873f976dcfc271c..e9d019cc8f46befa63bf382abbf9a53cc698b68b 100644 (file)
--- a/arch/arm/mach-davinci/da850.c
+++ b/arch/arm/mach-davinci/da850.c
@@ -367,6 +367,16 @@ static struct clk aemif_clk = {
        .flags          = ALWAYS_ENABLED,
 };
 
+/*
+ * In order to avoid adding the aemif_clk to the clock lookup table twice (and
+ * screwing up the linked list in the process) create a separate clock for
+ * nand inheriting the rate from aemif_clk.
+ */
+static struct clk aemif_nand_clk = {
+       .name           = "nand",
+       .parent         = &aemif_clk,
+};
+
 static struct clk usb11_clk = {
        .name           = "usb11",
        .parent         = &pll0_sysclk4,
@@ -537,7 +547,15 @@ static struct clk_lookup da850_clks[] = {
        CLK("da830-mmc.0",      NULL,           &mmcsd0_clk),
        CLK("da830-mmc.1",      NULL,           &mmcsd1_clk),
        CLK("ti-aemif",         NULL,           &aemif_clk),
-       CLK(NULL,               "aemif",        &aemif_clk),
+       /*
+        * The only user of this clock is davinci_nand and it get's it through
+        * con_id. The nand node itself is created from within the aemif
+        * driver to guarantee that it's probed after the aemif timing
+        * parameters are configured. of_dev_auxdata is not accessible from
+        * the aemif driver and can't be passed to of_platform_populate(). For
+        * that reason we're leaving the dev_id here as NULL.
+        */
+       CLK(NULL,               "aemif",        &aemif_nand_clk),
        CLK("ohci-da8xx",       "usb11",        &usb11_clk),
        CLK("musb-da8xx",       "usb20",        &usb20_clk),
        CLK("spi_davinci.0",    NULL,           &spi0_clk),