Attachment 34005 Details for Bug 26430 – fix i2c prescale calc

[patch] fix i2c prescale calc

0001-drm-radeon-kms-fix-i2c-prescale-calc-on-older-radeo.patch (text/plain), 2.01 KB, created by Alex Deucher on 2010-03-12 10:01:04 UTC

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Creator: Alex Deucher

Created: 2010-03-12 10:01:04 UTC

Size: 2.01 KB

patch

obsolete

>From b171bbe7de8e7aed10085ffde3aeb394416e498c Mon Sep 17 00:00:00 2001
>From: Alex Deucher <alexdeucher@gmail.com>
>Date: Fri, 12 Mar 2010 12:55:34 -0500
>Subject: [PATCH] drm/radeon/kms: fix i2c prescale calc on older radeons
>
>Should fix fdo bug 26430
>
>Signed-off-by: Alex Deucher <alexdeucher@gmail.com>
>---
> drivers/gpu/drm/radeon/radeon_i2c.c |   17 ++++++++---------
> 1 files changed, 8 insertions(+), 9 deletions(-)
>
>diff --git a/drivers/gpu/drm/radeon/radeon_i2c.c b/drivers/gpu/drm/radeon/radeon_i2c.c
>index 9ac94cf..f0200e5 100644
>--- a/drivers/gpu/drm/radeon/radeon_i2c.c
>+++ b/drivers/gpu/drm/radeon/radeon_i2c.c
>@@ -204,11 +204,10 @@ static void post_xfer(struct i2c_adapter *i2c_adap,
> 
> static u32 radeon_get_i2c_prescale(struct radeon_device *rdev)
> {
>-	struct radeon_pll *spll = &rdev->clock.spll;
> 	u32 sclk = radeon_get_engine_clock(rdev);
> 	u32 prescale = 0;
>-	u32 n, m;
>-	u8 loop;
>+	u32 nm;
>+	u8 n, m, loop;
> 	int i2c_clock;
> 
> 	switch (rdev->family) {
>@@ -224,13 +223,15 @@ static u32 radeon_get_i2c_prescale(struct radeon_device *rdev)
> 	case CHIP_R300:
> 	case CHIP_R350:
> 	case CHIP_RV350:
>-		n = (spll->reference_freq) / (4 * 6);
>+		i2c_clock = 60;
>+		nm = (sclk * 10) / (i2c_clock * 4);
> 		for (loop = 1; loop < 255; loop++) {
>-			if ((loop * (loop - 1)) > n)
>+			if ((nm / loop) < loop)
> 				break;
> 		}
>-		m = loop - 1;
>-		prescale = m | (loop << 8);
>+		n = loop - 1;
>+		m = loop - 2;
>+		prescale = m | (n << 8);
> 		break;
> 	case CHIP_RV380:
> 	case CHIP_RS400:
>@@ -238,7 +239,6 @@ static u32 radeon_get_i2c_prescale(struct radeon_device *rdev)
> 	case CHIP_R420:
> 	case CHIP_R423:
> 	case CHIP_RV410:
>-		sclk = radeon_get_engine_clock(rdev);
> 		prescale = (((sclk * 10)/(4 * 128 * 100) + 1) << 8) + 128;
> 		break;
> 	case CHIP_RS600:
>@@ -253,7 +253,6 @@ static u32 radeon_get_i2c_prescale(struct radeon_device *rdev)
> 	case CHIP_RV570:
> 	case CHIP_R580:
> 		i2c_clock = 50;
>-		sclk = radeon_get_engine_clock(rdev);
> 		if (rdev->family == CHIP_R520)
> 			prescale = (127 << 8) + ((sclk * 10) / (4 * 127 * i2c_clock));
> 		else
>-- 
>1.5.6.3
>

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Attachments on bug 26430: 33075 | 33076 | 33339 | 33498 | 33953 | 33961 | 33973 | 34005 | 34014 | 34042 | 34124

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