Hi Laurent,
(adding Mauro and LMML at Cc)
On 10/29/2013 11:28 PM, Laurent Pinchart wrote:
Hi Sylwester,
Thank you for the patch.
On Tuesday 29 October 2013 20:51:04 Sylwester Nawrocki wrote:
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 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.
Cc: Laurent Pinchart<laurent.pinchart@xxxxxxxxxxxxxxxx>
Signed-off-by: Sylwester Nawrocki<s.nawrocki@xxxxxxxxxxx>
Signed-off-by: Kyungmin Park<kyungmin.park@xxxxxxxxxxx>
Acked-by: Laurent Pinchart<laurent.pinchart@xxxxxxxxxxxxxxxx>
Do you plan to push this to mainline as part of this patch series ? I don't
have pending patches for the omap3isp that would conflict with this patch, so
that would be fine with me.
Thanks, yes I thought this patch might be merged together through the clk
tree, if Mike is willing to take it and we get yours and Mauro's Ack on it.
---
This patch has been "compile tested" only.
---
drivers/media/platform/omap3isp/isp.c | 22 ++++++++++++++++------
drivers/media/platform/omap3isp/isp.h | 1 +
2 files changed, 17 insertions(+), 6 deletions(-)
diff --git a/drivers/media/platform/omap3isp/isp.c
b/drivers/media/platform/omap3isp/isp.c index df3a0ec..286027a 100644
--- a/drivers/media/platform/omap3isp/isp.c
+++ b/drivers/media/platform/omap3isp/isp.c
@@ -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);
}
diff --git a/drivers/media/platform/omap3isp/isp.h
b/drivers/media/platform/omap3isp/isp.h index cd3eff4..1498f2b 100644
--- a/drivers/media/platform/omap3isp/isp.h
+++ b/drivers/media/platform/omap3isp/isp.h
@@ -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 */
--
Regards,
Sylwester
