Re: [EXT] [PATCH] PCI: imx6: Add L1SS support for i.MX8MQ

From: Andrey Smirnov
Date: Thu Jan 16 2020 - 09:37:24 EST


On Tue, Jan 14, 2020 at 7:26 PM Richard Zhu <hongxing.zhu@xxxxxxx> wrote:
>
>
> > -----Original Message-----
> > From: Andrey Smirnov <andrew.smirnov@xxxxxxxxx>
> > Sent: 2020å1æ15æ 1:03
> > To: linux-pci@xxxxxxxxxxxxxxx
> > Cc: Andrey Smirnov <andrew.smirnov@xxxxxxxxx>; Lorenzo Pieralisi
> > <lorenzo.pieralisi@xxxxxxx>; Bjorn Helgaas <bhelgaas@xxxxxxxxxx>; Chris
> > Healy <cphealy@xxxxxxxxx>; Lucas Stach <l.stach@xxxxxxxxxxxxxx>; Richard
> > Zhu <hongxing.zhu@xxxxxxx>; dl-linux-imx <linux-imx@xxxxxxx>;
> > linux-arm-kernel@xxxxxxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx
> > Subject: [EXT] [PATCH] PCI: imx6: Add L1SS support for i.MX8MQ
> >
> > Caution: EXT Email
> >
> > Add code to configure PCI IP block to utilize supported ASPM features.
> >
> > Signed-off-by: Andrey Smirnov <andrew.smirnov@xxxxxxxxx>
> [Richard Zhu] HI Andrey:
> This patch does the regmap to the src region, right?

Indeed.

> How about to add another reset to manipulate the *_OVERRIDE bit.
> Just like the following bits.
> resets = <&src IMX8MQ_RESET_PCIEPHY>,
> <&src IMX8MQ_RESET_PCIE_CTRL_APPS_EN>,
> <&src IMX8MQ_RESET_PCIE_CTRL_APPS_TURNOFF>;
> reset-names = "pciephy", "apps", "turnoff";
>

Last time I talked to Philipp Zabel (maintainer of reset subsystem) he
made it pretty clear that he though that exposing those PCIe related
bits via reset subsystem (for both imx7 and imx8mq) was a mistake and
going forward he'd like to see only true reset functionality to be
exposed that way. IMX8MQ_PCIE_CTRL_APPS_CLK_REQ is definitely not a
reset line, so the case for adding it to reset driver is even weaker.

Lucas, do you mind sharing your thoughts on this?

Thanks,
Andrey Smirnov