#10457 NORM Not Tri: Occasional SD command timeouts in OFW on XO-1.75

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#10457: Occasional SD command timeouts in OFW on XO-1.75
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 Reporter:  wad       |                 Owner:  wad        
     Type:  defect    |                Status:  new        
 Priority:  normal    |             Milestone:  Not Triaged
Component:  hardware  |               Version:  1.75-A1    
 Keywords:  XO-1.75   |           Next_action:  reproduce  
 Verified:  0         |   Deployment_affected:             
Blockedby:            |              Blocking:             
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 On one XO-1.75 A1 laptop (#12), running OFW Q4A05A, I have a probiem with
 the internal SD slot running at 50 MHz.  The external slot seems to
 operate fine.   Both slots are populated with Sandisk 4GB class 2 microSD
 cards.

 Problems were discovered using fs-update (trying to update the internal
 slot), and verified using "test int".  After one to five executions of
 "test int", OFW will start returning:

  SDHCI: Error: ISR = 8000 ESR = 1 Command Timeout

 As mentioned, the external slot runs fine at 50 MHz (as did both the
 internal and external slots of two other A1 MBs tested this afternoon ---
 #4 and #16).

 Running the slot at 25 MHz, by:

  dev /sd true to avoid-high-speed? dend

 resulted in the slot operating fine -- an fs-update was able to complete.

 First attempts to tune the timing failed, but the effects of the external
 RC dominate over most of the SOC timing.

-- 
Ticket URL: <http://dev.laptop.org/ticket/10457>
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