[haiku-bugs] Re: [Haiku] #10614: Radeon cards black screen on 64 bit hrev46950

  • From: "kallisti5" <trac@xxxxxxxxxxxx>
  • Date: Sat, 24 May 2014 21:46:42 -0000

#10614: Radeon cards black screen on 64 bit hrev46950
-------------------------+----------------------------
   Reporter:  vidrep     |      Owner:  nobody
       Type:  bug        |     Status:  new
   Priority:  normal     |  Milestone:  R1
  Component:  - General  |    Version:  R1/Development
 Resolution:             |   Keywords:
 Blocked By:             |   Blocking:  7665, 10536
Has a Patch:  0          |   Platform:  All
-------------------------+----------------------------

Comment (by kallisti5):

 I can confirm seeing this on my system as well. I accidently started
 troubleshooting it as part of a more general PLL calculation issue :-)

 The problem is here:
 {{{
 2008    radeon_hd: pll_compute: using minimum reference divider
 2009    radeon_hd: pll_compute: performing fractional feedback
 calculations
 2010    radeon_hd: pll_compute: Calculated pixel clock of 15 based on:
 2011    radeon_hd: pll_compute:   referenceFrequency: 1010;
 referenceDivider: 1025
 2012    radeon_hd: pll_compute:   feedbackDivider: 2048;
 feedbackDividerFrac: 0
 2013    radeon_hd: pll_compute:   postDivider: 127
 2014    radeon_hd: pll_compute: pixel clock 148500 was changed to 15
 }}}

 Your (and my) pixel clock is getting greatly reduced. This looks to be due
 to the referenceFrequency of "1010" (101 really is what it is pulling as
 referenceFrequency is * 10.

 1010 really isn't valid.


 On my card under x86_64 I dumped my AtomBIOS and the reference frequency
 is "2700", however atombios gets 1 at http://cgit.haiku-
 os.org/haiku/tree/src/add-ons/accelerants/radeon_hd/pll.cpp#n98...

 {{{
 KERN: radeon_hd: pll_compute: performing fractional feedback calculations
 KERN: radeon_hd: pll_compute: Calculated pixel clock of 9 based on:
 KERN: radeon_hd: pll_compute:   referenceFrequency: 10; referenceDivider:
 1025
 KERN: radeon_hd: pll_compute:   feedbackDivider: 2048;
 feedbackDividerFrac: 0
 KERN: radeon_hd: pll_compute:   postDivider: 2
 KERN: radeon_hd: pll_compute: pixel clock 148500 was changed to 9
 }}}

 Most likely due to a type issue somewhere... no idea where though.  Maybe
 somewhere in our AtomBIOS.

--
Ticket URL: <https://dev.haiku-os.org/ticket/10614#comment:4>
Haiku <https://dev.haiku-os.org>
Haiku - the operating system.

Other related posts: