[PATCH v2 3/3] media: qcom: camss: Fix overflows in clock rate calculations

From: Andrey Konovalov
Date: Wed Feb 17 2021 - 17:13:49 EST


From: Vladimir Lypak <junak.pub@xxxxxxxxx>

Because of u32 type being used to store pixel clock rate, expression used
to calculate pipeline clocks (pixel_clock * bpp) produces wrong value due
to integer overflow. This patch changes data type used to store, pass and
retrieve pixel_clock from u32 to u64 to make this mistake less likely to
be repeated in the future.

Signed-off-by: Vladimir Lypak <junak.pub@xxxxxxxxx>
Acked-by: Robert Foss <robert.foss@xxxxxxxxxx>
Signed-off-by: Andrey Konovalov <andrey.konovalov@xxxxxxxxxx>
---
drivers/media/platform/qcom/camss/camss-vfe.c | 4 ++--
drivers/media/platform/qcom/camss/camss.c | 2 +-
drivers/media/platform/qcom/camss/camss.h | 2 +-
3 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/media/platform/qcom/camss/camss-vfe.c b/drivers/media/platform/qcom/camss/camss-vfe.c
index fae2b513b2f9..b2c95b46ce66 100644
--- a/drivers/media/platform/qcom/camss/camss-vfe.c
+++ b/drivers/media/platform/qcom/camss/camss-vfe.c
@@ -1112,7 +1112,7 @@ static inline void vfe_isr_halt_ack(struct vfe_device *vfe)
static int vfe_set_clock_rates(struct vfe_device *vfe)
{
struct device *dev = vfe->camss->dev;
- u32 pixel_clock[MSM_VFE_LINE_NUM];
+ u64 pixel_clock[MSM_VFE_LINE_NUM];
int i, j;
int ret;

@@ -1194,7 +1194,7 @@ static int vfe_set_clock_rates(struct vfe_device *vfe)
*/
static int vfe_check_clock_rates(struct vfe_device *vfe)
{
- u32 pixel_clock[MSM_VFE_LINE_NUM];
+ u64 pixel_clock[MSM_VFE_LINE_NUM];
int i, j;
int ret;

diff --git a/drivers/media/platform/qcom/camss/camss.c b/drivers/media/platform/qcom/camss/camss.c
index eb8fb8c34acd..d82bbc2213a6 100644
--- a/drivers/media/platform/qcom/camss/camss.c
+++ b/drivers/media/platform/qcom/camss/camss.c
@@ -578,7 +578,7 @@ s64 camss_get_link_freq(struct media_entity *entity, unsigned int bpp,
*
* Return 0 on success or a negative error code otherwise
*/
-int camss_get_pixel_clock(struct media_entity *entity, u32 *pixel_clock)
+int camss_get_pixel_clock(struct media_entity *entity, u64 *pixel_clock)
{
struct media_entity *sensor;
struct v4l2_subdev *subdev;
diff --git a/drivers/media/platform/qcom/camss/camss.h b/drivers/media/platform/qcom/camss/camss.h
index 86cdc25189eb..e29466d07ad2 100644
--- a/drivers/media/platform/qcom/camss/camss.h
+++ b/drivers/media/platform/qcom/camss/camss.h
@@ -110,7 +110,7 @@ void camss_disable_clocks(int nclocks, struct camss_clock *clock);
struct media_entity *camss_find_sensor(struct media_entity *entity);
s64 camss_get_link_freq(struct media_entity *entity, unsigned int bpp,
unsigned int lanes);
-int camss_get_pixel_clock(struct media_entity *entity, u32 *pixel_clock);
+int camss_get_pixel_clock(struct media_entity *entity, u64 *pixel_clock);
int camss_pm_domain_on(struct camss *camss, int id);
void camss_pm_domain_off(struct camss *camss, int id);
void camss_delete(struct camss *camss);
--
2.17.1