* [PATCH 5.2 125/144] drm/i915: Fix wrong escape clock divisor init for GLK
[not found] <20190814165759.466811854@linuxfoundation.org>
@ 2019-08-14 17:01 ` Greg Kroah-Hartman
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From: Greg Kroah-Hartman @ 2019-08-14 17:01 UTC (permalink / raw)
To: linux-kernel; +Cc: Jani Nikula, Deepak M, Greg Kroah-Hartman, intel-gfx, stable
From: Stanislav Lisovskiy <stanislav.lisovskiy@intel.com>
commit 73a0ff0b30af79bf0303d557eb82f1d1945bb6ee upstream.
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: bcc657004841 ("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 ce52ad5dd52cfaf3398058384e0ff94134bbd89c)
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/gpu/drm/i915/vlv_dsi_pll.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
--- a/drivers/gpu/drm/i915/vlv_dsi_pll.c
+++ b/drivers/gpu/drm/i915/vlv_dsi_pll.c
@@ -394,8 +394,8 @@ static void glk_dsi_program_esc_clock(st
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 */
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