Re: [PATCH v3 1/9] ARM: dts: imx6qdl: Specify IMX6QDL_CLK_IPG as "ipg" clock to SDMA

From: Shawn Guo
Date: Sat Apr 20 2019 - 09:34:52 EST


On Sat, Apr 20, 2019 at 07:14:26AM -0500, Adam Ford wrote:
> On Wed, Apr 10, 2019 at 9:30 PM Shawn Guo <shawnguo@xxxxxxxxxx> wrote:
> >
> > On Thu, Mar 28, 2019 at 11:49:16PM -0700, Andrey Smirnov wrote:
> > > Since 25aaa75df1e6 SDMA driver uses clock rates of "ipg" and "ahb"
> > > clock to determine if it needs to configure the IP block as operating
> > > at 1:1 or 1:2 clock ratio (ACR bit in SDMAARM_CONFIG). Specifying both
> > > clocks as IMX6QDL_CLK_SDMA results in driver incorrectly thinking that
> > > ratio is 1:1 which results in broken SDMA funtionality(this at least
> > > breaks RAVE SP serdev driver on RDU2). Fix the code to specify
> > > IMX6QDL_CLK_IPG as "ipg" clock for SDMA, to avoid detecting incorrect
> > > clock ratio.
> > >
> > > Fixes: 25aaa75df1e6 ("dmaengine: imx-sdma: add clock ratio 1:1 check")
> >
> > Since we have a fix in the dma driver, I dropped the Fixes tag here.
> >
> > Applied all, thanks.
>
> Do you know if the SDMA fixes will be back-ported to 5.0.y branch? To
> get 5.0 working, I need to manually apply the patches.

I'm confused here. The regression was caused by 25aaa75df1e6
("dmaengine: imx-sdma: add clock ratio 1:1 check"), which only lands on
mainline with v5.1-rc1. How would 5.0.y branch need fixing?

Shawn