s5p-mfc: Fix clock management in s5p_mfc_release() function

commit c0026c7bfb95c250c3e34fde59f96ad72fd730d6 upstream.

Clock control indirectly requires access to MFC device, so call it only
if we are sure that the device exists in s5p_mfc_release function.
s5p_mfc_remove() calls s5p_mfc_final_pm(), which releases all PM related
resources, including clocks, so any call to clocks related functions
is not valid after s5p_mfc_final_pm().

Fixes: d695c12 ("[media] media: s5p-mfc fix invalid memory access from
s5p_mfc_release()")

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/media/platform/s5p-mfc/s5p_mfc.c b/drivers/media/platform/s5p-mfc/s5p_mfc.c
index 3436eda5885599f56842315fdd3650a0fc0cc951..27e7cf65c2a77a367fa1c8ce0537ab29040fac9d 100644 (file)
--- a/drivers/media/platform/s5p-mfc/s5p_mfc.c
+++ b/drivers/media/platform/s5p-mfc/s5p_mfc.c
@@ -926,10 +926,11 @@ static int s5p_mfc_release(struct file *file)
        mfc_debug_enter();
        if (dev)
                mutex_lock(&dev->mfc_mutex);
-       s5p_mfc_clock_on();
        vb2_queue_release(&ctx->vq_src);
        vb2_queue_release(&ctx->vq_dst);
        if (dev) {
+               s5p_mfc_clock_on();
+
                /* Mark context as idle */
                clear_work_bit_irqsave(ctx);
                /*
@@ -951,9 +952,9 @@ static int s5p_mfc_release(struct file *file)
                        if (s5p_mfc_power_off() < 0)
                                mfc_err("Power off failed\n");
                }
+               mfc_debug(2, "Shutting down clock\n");
+               s5p_mfc_clock_off();
        }
-       mfc_debug(2, "Shutting down clock\n");
-       s5p_mfc_clock_off();
        if (dev)
                dev->ctx[ctx->num] = NULL;
        s5p_mfc_dec_ctrls_delete(ctx);