> Ulf Hansson <ulf.hansson@xxxxxxxxxx> 於 2021年1月14日 週四 下午8:04寫道： > > On Thu, 14 Jan 2021 at 07:25, 陳建宏 <reniuschengl@xxxxxxxxx> wrote: > > > > > Ulf Hansson <ulf.hansson@xxxxxxxxxx> 於 2021年1月13日 週三 下午6:53寫道： > > > > > > On Wed, 6 Jan 2021 at 10:27, Renius Chen <reniuschengl@xxxxxxxxx> wrote: > > > > > > > > The R/W performance of GL9763E is low with some platforms, which > > > > support ASPM mechanism, due to entering L1 state very frequently > > > > in R/W process. Enlarge its ASPM L1 entry delay to improve the > > > > R/W performance of GL9763E. > > > > > > What do you mean by frequently? In between a burst of request or > > > during a burst of request? > > > > GL9763E enters ASPM L1 state after a very short idle in default, even > > during a burst of request. > > Okay, then it certainly makes sense to extend the idle period. > > Would you mind extending the commit message with some of this > information, as I think it's useful. > > > > > > I am thinking that this could have an effect on energy instead, but I > > > guess it's not always straightforward to decide what's most important. > > > > > > Anyway, what does it mean when you change to use 0x3FF? Are you > > > increasing the idle period? Then for how long? > > > > Yes, we considered that having high performance is more important than > > saving power during a burst of request. > > So we increased the idle period for 260us, by setting 0x3FF to the > > ASPM L1 entry delay bits of our vendor-specific register. > > Anyway, GL9763E can still enter ASPM L1 state by a longer idle. > > Most mmc controllers that uses runtime PM autosuspend for the same > reasons, uses and idle period time of ~50us. 260us is in the same > ballpark, so I am fine with that, if that works for you. > > However, can you please add a comment in the code (and preferably also > to the commit message) that 0x3FF means using a 260us idle period? OK, I'll extend the commit message with some of these information and add a comment in the code to describe that the idle period is set to 260us. Then I'll submit a newer version: mmc: sdhci-pci-gli: Enlarge ASPM L1 entry delay of GL9763E (v2). Thank you. > > [...] > > Kind regards > Uffe
