openkylin
/
linux
mirror of https://gitee.com/openkylin/linux.git
9
0
Fork 0
Code Issues Projects Releases Wiki Activity

omap3isp: Modify clocks registration to avoid circular references 

The clock core code is going to be modified so clk_get() takes
reference on the clock provider module. Until the potential circular
reference issue is properly addressed, we pass NULL as the first
argument to clk_register(), in order to disallow sub-devices taking
a reference on the ISP module back trough clk_get(). This should
prevent locking the modules in memory.

Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
This commit is contained in:
Sylwester Nawrocki 2013-10-29 20:51:04 +01:00
parent 1d9438f7b5
commit 4eadfc38c4
2 changed files with 17 additions and 6 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

22
drivers/media/platform/omap3isp/isp.c
View File

@ -290,9 +290,11 @@ static int isp_xclk_init(struct isp_device *isp)
struct clk_init_data init;
unsigned int i;
for (i = 0; i < ARRAY_SIZE(isp->xclks); ++i)
isp->xclks[i].clk = ERR_PTR(-EINVAL);
for (i = 0; i < ARRAY_SIZE(isp->xclks); ++i) {
struct isp_xclk *xclk = &isp->xclks[i];
struct clk *clk;
xclk->isp = isp;
xclk->id = i == 0 ? ISP_XCLK_A : ISP_XCLK_B;
@ -305,10 +307,15 @@ static int isp_xclk_init(struct isp_device *isp)
init.num_parents = 1;
xclk->hw.init = &init;
clk = devm_clk_register(isp->dev, &xclk->hw);
if (IS_ERR(clk))
return PTR_ERR(clk);
/*
* The first argument is NULL in order to avoid circular
* reference, as this driver takes reference on the
* sensor subdevice modules and the sensors would take
* reference on this module through clk_get().
*/
xclk->clk = clk_register(NULL, &xclk->hw);
if (IS_ERR(xclk->clk))
return PTR_ERR(xclk->clk);
if (pdata->xclks[i].con_id == NULL &&
pdata->xclks[i].dev_id == NULL)
@ -320,7 +327,7 @@ static int isp_xclk_init(struct isp_device *isp)
xclk->lookup->con_id = pdata->xclks[i].con_id;
xclk->lookup->dev_id = pdata->xclks[i].dev_id;
xclk->lookup->clk = clk;
xclk->lookup->clk = xclk->clk;
clkdev_add(xclk->lookup);
}
@ -335,6 +342,9 @@ static void isp_xclk_cleanup(struct isp_device *isp)
for (i = 0; i < ARRAY_SIZE(isp->xclks); ++i) {
struct isp_xclk *xclk = &isp->xclks[i];
if (!IS_ERR(xclk->clk))
clk_unregister(xclk->clk);
if (xclk->lookup)
clkdev_drop(xclk->lookup);
}

1
drivers/media/platform/omap3isp/isp.h
View File

@ -135,6 +135,7 @@ struct isp_xclk {
struct isp_device *isp;
struct clk_hw hw;
struct clk_lookup *lookup;
struct clk *clk;
enum isp_xclk_id id;
spinlock_t lock; /* Protects enabled and divider */