From 73a0ff0b30af79bf0303d557eb82f1d1945bb6ee Mon Sep 17 00:00:00 2001 From: Stanislav Lisovskiy Date: Fri, 12 Jul 2019 11:19:38 +0300 Subject: drm/i915: Fix wrong escape clock divisor init for GLK According to Bspec clock divisor registers in GeminiLake should be initialized by shifting 1(<<) to amount of correspondent divisor. While i915 was writing all this time that value as is. Surprisingly that it by accident worked, until we met some issues with Microtech Etab. v2: Added Fixes tag and cc v3: Added stable to cc as well. Signed-off-by: Stanislav Lisovskiy Reviewed-by: Vandita Kulkarni Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=108826 Fixes: bcc657004841 ("drm/i915/glk: Program txesc clock divider for GLK") Cc: Deepak M Cc: Madhav Chauhan Cc: Jani Nikula Cc: Jani Nikula Cc: Joonas Lahtinen Cc: Rodrigo Vivi Cc: intel-gfx@lists.freedesktop.org Cc: stable@vger.kernel.org Signed-off-by: Jani Nikula Link: https://patchwork.freedesktop.org/patch/msgid/20190712081938.14185-1-stanislav.lisovskiy@intel.com (cherry picked from commit ce52ad5dd52cfaf3398058384e0ff94134bbd89c) Signed-off-by: Jani Nikula --- drivers/gpu/drm/i915/display/vlv_dsi_pll.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'drivers/gpu') diff --git a/drivers/gpu/drm/i915/display/vlv_dsi_pll.c b/drivers/gpu/drm/i915/display/vlv_dsi_pll.c index 99cc3e2e9c2c..f016a776a39e 100644 --- a/drivers/gpu/drm/i915/display/vlv_dsi_pll.c +++ b/drivers/gpu/drm/i915/display/vlv_dsi_pll.c @@ -396,8 +396,8 @@ static void glk_dsi_program_esc_clock(struct drm_device *dev, else txesc2_div = 10; - I915_WRITE(MIPIO_TXESC_CLK_DIV1, txesc1_div & GLK_TX_ESC_CLK_DIV1_MASK); - I915_WRITE(MIPIO_TXESC_CLK_DIV2, txesc2_div & GLK_TX_ESC_CLK_DIV2_MASK); + I915_WRITE(MIPIO_TXESC_CLK_DIV1, (1 << (txesc1_div - 1)) & GLK_TX_ESC_CLK_DIV1_MASK); + I915_WRITE(MIPIO_TXESC_CLK_DIV2, (1 << (txesc2_div - 1)) & GLK_TX_ESC_CLK_DIV2_MASK); } /* Program BXT Mipi clocks and dividers */ -- cgit v1.2.3-59-g8ed1b