drm/nouveau/bios/ramcfg, setting of RON pull value

[Colin Ian King]

Hi,

Static Analysis with CoverityScan as detected an issue with the setting
of the RON pull value in function nvkm_gddr3_calc in
drm/nouveau/bios/ramcfg.c

This was introduced by commit: c25bf7b6155cb ("drm/nouveau/bios/ramcfg:
Separate out RON pull value")

CoverityScan reports the issue as follows:

 84        case 0x20:
 85                CWL = (ram->next->bios.timing[1] & 0x00000f80) >> 7;
 86                CL  = (ram->next->bios.timing[1] & 0x0000001f) >> 0;
 87                WR  = (ram->next->bios.timing[2] & 0x007f0000) >> 16;
 88                /* XXX: Get these values from the VBIOS instead */
 89                DLL = !(ram->mr[1] & 0x1);

   CID 1324005 (#1 of 1): Operands don't affect result
(CONSTANT_EXPRESSION_RESULT)

result_independent_of_operands: !(ram->mr[1] & 768) >> 8 is 0 regardless
of the values of its operands. This occurs as the operand of assignment.

 90                RON = !(ram->mr[1] & 0x300) >> 8;
 91                break;

Looking at this, I believe perhaps the correct setting could be:

RON = !((ram->mr[1] & 0x300) >> 8);

..however I don't have the datasheet available for the H/W so I'm not
sure if this a correct fix.

Colin