On 8/10/23 14:46, Adam Ford wrote:
On Thu, Aug 10, 2023 at 2:42 AM Marco Felsch <m.felsch@xxxxxxxxxxxxxx> wrote:
Hi Marek,
On 23-08-10, Marek Vasut wrote:
Update VPU clock according to reference manual to improve performance.
i.MX 8M Plus Applications Processor Reference Manual, Rev. 1, 06/2021
Table 5-1. Clock Root Table (continued) reads as follows:
Clock Root ............... Max Freq (MHz)
VPU_BUS_CLK_ROOT ......... 800
VPU_G1_CLK_ROOT .......... 800
VPU_G2_CLK_ROOT .......... 700
5.1.5.1 Input Clocks
Input Clock .............. Frequency (MHz)
VPU_PLL_CLK .............. 800
Acoording the datasheet not the reference manual, this would be the
overdrive mode now. Can we ensure that VDD_SOC is in overdrive state?
Shoot, I explicitly searched the TRM for overdrive, because I remember
this coming before with either the 8MQ or 8MM, but I couldn't
remember. I forgot all about the actual datasheet.
Same here, I vaguely recall there might've been a reason why those lower
freqs, but I couldn't find it either.
The operating-points for the various voltage rails would have to
increase to get this into overdrive mode. I think this would have to
be done on a per-board basis if memory serves when this came up
before. :-(
I don't mind doing it per board. Actually, I don't mind dropping this
patch, since the decoding performance increase is not even an issue in
any of the use cases I care about.
I guess the general agreement here is to go with the "nominal mode" by
default and enable "overdrive mode" per-board , while the NXP downstream
goes full "overdrive mode" all the time ?
