| Message ID | 20241007050157.26855-2-jonathan@marek.ca (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v2,1/2] drm/msm/dsi: improve/fix dsc pclk calculation | expand |
On Mon, Oct 07, 2024 at 01:01:49AM GMT, Jonathan Marek wrote: > When (mode->clock * 1000) is larger than (1<<31), int to unsigned long > conversion will sign extend the int to 64 bits and the pclk_rate value > will be incorrect. > > Fix this by making the result of the multiplication unsigned. > > Note that above (1<<32) would still be broken and require more changes, but > its unlikely anyone will need that anytime soon. > > Fixes: c4d8cfe516dc ("drm/msm/dsi: add implementation for helper functions") > Signed-off-by: Jonathan Marek <jonathan@marek.ca> > --- > drivers/gpu/drm/msm/dsi/dsi_host.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
On 10/6/2024 10:01 PM, Jonathan Marek wrote: > When (mode->clock * 1000) is larger than (1<<31), int to unsigned long > conversion will sign extend the int to 64 bits and the pclk_rate value > will be incorrect. > > Fix this by making the result of the multiplication unsigned. > > Note that above (1<<32) would still be broken and require more changes, but > its unlikely anyone will need that anytime soon. > > Fixes: c4d8cfe516dc ("drm/msm/dsi: add implementation for helper functions") > Signed-off-by: Jonathan Marek <jonathan@marek.ca> > --- > drivers/gpu/drm/msm/dsi/dsi_host.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > Reviewed-by: Abhinav Kumar <quic_abhinavk@quicinc.com>
diff --git a/drivers/gpu/drm/msm/dsi/dsi_host.c b/drivers/gpu/drm/msm/dsi/dsi_host.c index 1205aa398e445..a98d24b7cb00b 100644 --- a/drivers/gpu/drm/msm/dsi/dsi_host.c +++ b/drivers/gpu/drm/msm/dsi/dsi_host.c @@ -550,7 +550,7 @@ static unsigned long dsi_get_pclk_rate(const struct drm_display_mode *mode, { unsigned long pclk_rate; - pclk_rate = mode->clock * 1000; + pclk_rate = mode->clock * 1000u; if (dsc) pclk_rate = dsi_adjust_pclk_for_compression(mode, dsc);
When (mode->clock * 1000) is larger than (1<<31), int to unsigned long conversion will sign extend the int to 64 bits and the pclk_rate value will be incorrect. Fix this by making the result of the multiplication unsigned. Note that above (1<<32) would still be broken and require more changes, but its unlikely anyone will need that anytime soon. Fixes: c4d8cfe516dc ("drm/msm/dsi: add implementation for helper functions") Signed-off-by: Jonathan Marek <jonathan@marek.ca> --- drivers/gpu/drm/msm/dsi/dsi_host.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)