ARM: OMAP: Fix McBSP spin_lock deadlock
A spin_lock deadlock will occur when omap_mcbsp_request() is invoked.
omap_mcbsp_request()
\- clk_enable(mcbsp->clk) [takes and holds clockfw_lock]
\- omap2_clk_enable()
\- _omap2_clk_enable()
\- omap_mcbsp_clk_enable()
\- clk_enable(child clock) [tries for clockfw_lock again]
mcbsp_clk is a virtual clock and it comprises several child clocks. when
enable mcbsp_clk in omap_mcbsp_request(), the enable function of mcbsp_clk
will enable its child clocks, then the deadlock occurs.
The solution is to remove the virtual clock and enable these child clocks in
omap_mcbsp_request() directly.
Signed-off-by: Stanley.Miao <stanley.miao@windriver.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
diff --git a/arch/arm/mach-omap1/mcbsp.c b/arch/arm/mach-omap1/mcbsp.c
index ca7a0cc..575ba31 100644
--- a/arch/arm/mach-omap1/mcbsp.c
+++ b/arch/arm/mach-omap1/mcbsp.c
@@ -28,81 +28,8 @@
#define DPS_RSTCT2_PER_EN (1 << 0)
#define DSP_RSTCT2_WD_PER_EN (1 << 1)
-struct mcbsp_internal_clk {
- struct clk clk;
- struct clk **childs;
- int n_childs;
-};
-
#if defined(CONFIG_ARCH_OMAP15XX) || defined(CONFIG_ARCH_OMAP16XX)
-static void omap_mcbsp_clk_init(struct mcbsp_internal_clk *mclk)
-{
- const char *clk_names[] = { "dsp_ck", "api_ck", "dspxor_ck" };
- int i;
-
- mclk->n_childs = ARRAY_SIZE(clk_names);
- mclk->childs = kzalloc(mclk->n_childs * sizeof(struct clk *),
- GFP_KERNEL);
-
- for (i = 0; i < mclk->n_childs; i++) {
- /* We fake a platform device to get correct device id */
- struct platform_device pdev;
-
- pdev.dev.bus = &platform_bus_type;
- pdev.id = mclk->clk.id;
- mclk->childs[i] = clk_get(&pdev.dev, clk_names[i]);
- if (IS_ERR(mclk->childs[i]))
- printk(KERN_ERR "Could not get clock %s (%d).\n",
- clk_names[i], mclk->clk.id);
- }
-}
-
-static int omap_mcbsp_clk_enable(struct clk *clk)
-{
- struct mcbsp_internal_clk *mclk = container_of(clk,
- struct mcbsp_internal_clk, clk);
- int i;
-
- for (i = 0; i < mclk->n_childs; i++)
- clk_enable(mclk->childs[i]);
- return 0;
-}
-
-static void omap_mcbsp_clk_disable(struct clk *clk)
-{
- struct mcbsp_internal_clk *mclk = container_of(clk,
- struct mcbsp_internal_clk, clk);
- int i;
-
- for (i = 0; i < mclk->n_childs; i++)
- clk_disable(mclk->childs[i]);
-}
-
-static struct mcbsp_internal_clk omap_mcbsp_clks[] = {
- {
- .clk = {
- .name = "mcbsp_clk",
- .id = 1,
- .enable = omap_mcbsp_clk_enable,
- .disable = omap_mcbsp_clk_disable,
- },
- },
- {
- .clk = {
- .name = "mcbsp_clk",
- .id = 3,
- .enable = omap_mcbsp_clk_enable,
- .disable = omap_mcbsp_clk_disable,
- },
- },
-};
-
-#define omap_mcbsp_clks_size ARRAY_SIZE(omap_mcbsp_clks)
-#else
-#define omap_mcbsp_clks_size 0
-static struct mcbsp_internal_clk __initdata *omap_mcbsp_clks;
-static inline void omap_mcbsp_clk_init(struct mcbsp_internal_clk *mclk)
-{ }
+const char *clk_names[] = { "dsp_ck", "api_ck", "dspxor_ck" };
#endif
static void omap1_mcbsp_request(unsigned int id)
@@ -167,8 +94,9 @@
.rx_irq = INT_McBSP1RX,
.tx_irq = INT_McBSP1TX,
.ops = &omap1_mcbsp_ops,
- .clk_name = "mcbsp_clk",
- },
+ .clk_names = clk_names,
+ .num_clks = 3,
+ },
{
.phys_base = OMAP1510_MCBSP2_BASE,
.dma_rx_sync = OMAP_DMA_MCBSP2_RX,
@@ -184,7 +112,8 @@
.rx_irq = INT_McBSP3RX,
.tx_irq = INT_McBSP3TX,
.ops = &omap1_mcbsp_ops,
- .clk_name = "mcbsp_clk",
+ .clk_names = clk_names,
+ .num_clks = 3,
},
};
#define OMAP15XX_MCBSP_PDATA_SZ ARRAY_SIZE(omap15xx_mcbsp_pdata)
@@ -202,7 +131,8 @@
.rx_irq = INT_McBSP1RX,
.tx_irq = INT_McBSP1TX,
.ops = &omap1_mcbsp_ops,
- .clk_name = "mcbsp_clk",
+ .clk_names = clk_names,
+ .num_clks = 3,
},
{
.phys_base = OMAP1610_MCBSP2_BASE,
@@ -219,7 +149,8 @@
.rx_irq = INT_McBSP3RX,
.tx_irq = INT_McBSP3TX,
.ops = &omap1_mcbsp_ops,
- .clk_name = "mcbsp_clk",
+ .clk_names = clk_names,
+ .num_clks = 3,
},
};
#define OMAP16XX_MCBSP_PDATA_SZ ARRAY_SIZE(omap16xx_mcbsp_pdata)
@@ -230,15 +161,6 @@
int __init omap1_mcbsp_init(void)
{
- int i;
-
- for (i = 0; i < omap_mcbsp_clks_size; i++) {
- if (cpu_is_omap15xx() || cpu_is_omap16xx()) {
- omap_mcbsp_clk_init(&omap_mcbsp_clks[i]);
- clk_register(&omap_mcbsp_clks[i].clk);
- }
- }
-
if (cpu_is_omap730())
omap_mcbsp_count = OMAP730_MCBSP_PDATA_SZ;
if (cpu_is_omap15xx())