drm/nv50: improve nv50_pm_get_clock()

Many of the nv50 cards have their shader and/or memory pll
disabled at some stage.
This patch addresses those cases, so that the function
returns the correct frequency.

When the shader pll is disabled, the blob reports 2*core clock
Whereas for memory, the data stored in the vbios. This action
is incorrect as some vbioses store a clock value that is less
than the refference clock of the pll.

Thus we are reporting the reff_clk as it is the frequency the
pll actually operates

v2 - Convert NV_INFO() messages to NV_DEBUG()
Provide more information in the actuall message

Signed-off-by: Emil Velikov <emil.l.velikov@gmail.com>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
This commit is contained in:
Emil Velikov 2011-04-11 20:43:23 +01:00 committed by Ben Skeggs
parent 1f962797fb
commit 619d4f7e21

View File

@ -47,6 +47,21 @@ nv50_pm_clock_get(struct drm_device *dev, u32 id)
reg0 = nv_rd32(dev, pll.reg + 0);
reg1 = nv_rd32(dev, pll.reg + 4);
if ((reg0 & 0x80000000) == 0) {
if (id == PLL_SHADER) {
NV_DEBUG(dev, "Shader PLL is disabled. "
"Shader clock is twice the core\n");
ret = nv50_pm_clock_get(dev, PLL_CORE);
if (ret > 0)
return ret << 1;
} else if (id == PLL_MEMORY) {
NV_DEBUG(dev, "Memory PLL is disabled. "
"Memory clock is equal to the ref_clk\n");
return pll.refclk;
}
}
P = (reg0 & 0x00070000) >> 16;
N = (reg1 & 0x0000ff00) >> 8;
M = (reg1 & 0x000000ff);