Nathan Ciobanu bb5ffe6fd5 drm/i915/dp: Limit link training clock recovery loop ... Limit the link training clock recovery loop to 10 attempts at LANEx_CR_DONE per DP 1.4 spec section 3.5.1.2.2 and 80 attempts for pre-DP 1.4 (4 voltage levels x 4 preemphasis levels x x 5 identical voltages tries). Some faulty USB-C MST hubs can cause us to get stuck in this loop indefinitely requesting something like: voltage swing: 0, pre-emphasis level: 2 voltage swing: 1, pre-emphasis level: 2 voltage swing: 0, pre-emphasis level: 3 over and over so max_vswing would never be reached, drm_dp_clock_recovery_ok() would never return true and voltage_tries would always get reset to 1. The driver sends those values to the hub but the hub keeps requesting new values every time. Changes in v2: - updated commit message (DK, Manasi) - defined DP_DP14_MAX_CR_TRIES (Marc) - made the loop iterate for max 10 times (Rodrigo, Marc) Changes in v3: - changed error message to use DP_DP14_MAX_CR_TRIES Changes in v4: - Updated the title to reflect the change - Updated the commit message - Added 80 attempts for pre-DP 1.4 devices Changes in v5: - Removed DP_DP14_MAX_CR_TRIES from drm v6: Updated comment to match kernel style (Rodrigo) Cc: Dhinakaran Pandiyan <dhinakaran.pandiyan@intel.com> Cc: Rodrigo Vivi <rodrigo.vivi@intel.com> Cc: Marc Herbert <marc.herbert@intel.com> Cc: Manasi Navare <manasi.d.navare@intel.com> Signed-off-by: Nathan Ciobanu <nathan.d.ciobanu@linux.intel.com> Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com> Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20180720214413.29506-1-rodrigo.vivi@intel.com		2018-07-23 15:59:44 -07:00
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drm	drm/i915/dp: Limit link training clock recovery loop	2018-07-23 15:59:44 -07:00
host1x	drm for v4.18-rc1	2018-06-06 08:16:33 -07:00
ipu-v3
vga	docs: Fix some broken references	2018-06-15 18:10:01 -03:00
Makefile