gpu: ipu-v3: limit pixel clock divider to 8-bits
The DI pixel clock divider bit field is only 8 bits wide for the
integer part, so limit the divider to the 1...255 interval before
deciding whether the internal clock can be used and before writing
to the register.
Reported-by: Felix Mellmann <felix.mellmann@gmail.com>
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
diff --git a/drivers/gpu/ipu-v3/ipu-di.c b/drivers/gpu/ipu-v3/ipu-di.c
index 3ddfb3d..2970c6b 100644
--- a/drivers/gpu/ipu-v3/ipu-di.c
+++ b/drivers/gpu/ipu-v3/ipu-di.c
@@ -441,8 +441,7 @@
in_rate = clk_get_rate(clk);
div = DIV_ROUND_CLOSEST(in_rate, sig->mode.pixelclock);
- if (div == 0)
- div = 1;
+ div = clamp(div, 1U, 255U);
clkgen0 = div << 4;
}
@@ -459,8 +458,7 @@
clkrate = clk_get_rate(di->clk_ipu);
div = DIV_ROUND_CLOSEST(clkrate, sig->mode.pixelclock);
- if (div == 0)
- div = 1;
+ div = clamp(div, 1U, 255U);
rate = clkrate / div;
error = rate / (sig->mode.pixelclock / 1000);
@@ -483,8 +481,7 @@
in_rate = clk_get_rate(clk);
div = DIV_ROUND_CLOSEST(in_rate, sig->mode.pixelclock);
- if (div == 0)
- div = 1;
+ div = clamp(div, 1U, 255U);
clkgen0 = div << 4;
}