On Mon, Nov 02, 2015 at 09:18:55AM +0000, Charles Keepax wrote:
On Mon, Nov 02, 2015 at 04:44:04PM +0800, Zidan Wang wrote:
Hi Mark,
In wm8960 codec driver, suspend_bias_off has been enabled. So when system suspend, the wm8960 codec will go to bias off, it will disable VMID and VREF, then sleep 600ms. It seems that 600ms is too long for system suspend.
Because the wm8960 datasheet don't mentioned the sleep time, so i want to check with you if we can shorten the sleep time.
I can't say that I am explicit familiar with the required delay there, but the comment in the code says that we are letting VMID and VREF discharge, which I certainly could believe would take a while. My guess would be that we likely weren't super excited about putting a 600mS delay in, which probably means it was necessary for some reason.
How much where you hoping to reduce it by? I can see if I can find a hardware engineer who still remembers enough about the part to discuss it with.
Some customer can't accept such long system suspend time. It's better to spend less than 100ms for system suspend. Codec suspend is a part of system suspend, so it should be less than 100ms, and as short as possible.
Best Regards, Zidan Wang
Thanks, Charles