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drm/i915: Fix wrong escape clock divisor init for GLK

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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 <stanislav.lisovskiy@intel.com>
Reviewed-by: Vandita Kulkarni <vandita.kulkarni@intel.com>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=108826
Fixes: bcc6570048 ("drm/i915/glk: Program txesc clock divider for GLK")
Cc: Deepak M <m.deepak@intel.com>
Cc: Madhav Chauhan <madhav.chauhan@intel.com>
Cc: Jani Nikula <jani.nikula@intel.com>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: intel-gfx@lists.freedesktop.org
Cc: stable@vger.kernel.org
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190712081938.14185-1-stanislav.lisovskiy@intel.com
(cherry picked from commit ce52ad5dd5)
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
This commit is contained in:
Stanislav Lisovskiy 2019-07-12 11:19:38 +03:00 committed by Jani Nikula
parent 0584674d7f
commit 73a0ff0b30
1 changed files with 2 additions and 2 deletions
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4
drivers/gpu/drm/i915/display/vlv_dsi_pll.c
View File

@ -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 */