Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit d0c96d16 authored by Russell King's avatar Russell King
Browse files

drm: bridge/dw_hdmi: avoid being recursive in N calculation 



There's no need to be recursive when computing the N value for the ACR
packet - we can instead calculate the multiplier prior to our switch()
based lookup, and multiply the N value appropriately afterwards.

Tested-by: default avatarFabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
parent 91cd6908

drivers/gpu/drm/bridge/dw_hdmi.c

+9 −16
Original line number Diff line number Diff line
@@ -221,6 +221,12 @@ static unsigned int hdmi_compute_n(unsigned int freq, unsigned long pixel_clk, 
				   unsigned int ratio)

{

	unsigned int n = (128 * freq) / 1000;

	unsigned int mult = 1;



	while (freq > 48000) {

		mult *= 2;

		freq /= 2;

	}



	switch (freq) {

	case 32000:
@@ -232,6 +238,7 @@ static unsigned int hdmi_compute_n(unsigned int freq, unsigned long pixel_clk, 
			n = 11648;

		else

			n = 4096;

		n *= mult;

		break;



	case 44100:
@@ -243,6 +250,7 @@ static unsigned int hdmi_compute_n(unsigned int freq, unsigned long pixel_clk, 
			n = (ratio == 150) ? 17836 : 8918;

		else

			n = 6272;

		n *= mult;

		break;



	case 48000:
@@ -256,22 +264,7 @@ static unsigned int hdmi_compute_n(unsigned int freq, unsigned long pixel_clk, 
			n = (ratio == 150) ? 11648 : 5824;

		else

			n = 6144;

		break;



	case 88200:

		n = hdmi_compute_n(44100, pixel_clk, ratio) * 2;

		break;



	case 96000:

		n = hdmi_compute_n(48000, pixel_clk, ratio) * 2;

		break;



	case 176400:

		n = hdmi_compute_n(44100, pixel_clk, ratio) * 4;

		break;



	case 192000:

		n = hdmi_compute_n(48000, pixel_clk, ratio) * 4;

		n *= mult;

		break;



	default: