While I thought I had this correct (since it actually did reject modes like I expected during testing), Ville Syrjala from Intel pointed out that the logic here isn't correct. max_clock refers to the max data rate supported by the DP encoder. So, limiting it to the output of ds_clock (which refers to the maximum dotclock of the downstream DP device) doesn't make any sense. Additionally, since we're using the connector's bpc as the canonical BPC we should use this in mode_valid until we support dynamically setting the bpp based on bandwidth constraints. https://lists.freedesktop.org/archives/dri-devel/2020-September/280276.html For more info. So, let's rewrite this using Ville's advice. v2: * Ville pointed out I mixed up the dotclock and the link rate. So fix that... * ...and also rename all the variables in this function to be more appropriately labeled so I stop mixing them up. * Reuse the bpp from the connector for now until we have dynamic bpp selection. * Use use DIV_ROUND_UP for calculating the mode rate like i915 does, which we should also have been doing from the start Signed-off-by: Lyude Paul <lyude@redhat.com> Fixes: 409d38139b42 ("drm/nouveau/kms/nv50-: Use downstream DP clock limits for mode validation") Cc: Ville Syrjälä <ville.syrjala@linux.intel.com> Cc: Lyude Paul <lyude@redhat.com> Cc: Ben Skeggs <bskeggs@redhat.com> Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
Linux kernel ============ There are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. Please read Documentation/admin-guide/README.rst first. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. The formatted documentation can also be read online at: https://www.kernel.org/doc/html/latest/ There are various text files in the Documentation/ subdirectory, several of them using the Restructured Text markup notation. Please read the Documentation/process/changes.rst file, as it contains the requirements for building and running the kernel, and information about the problems which may result by upgrading your kernel.
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