RE: [EXT] Re: [PATCH v3 net 2/2] net: stmmac: dwmac-imx: pause the TXC clock in fixed-link

From: Shenwei Wang
Date: Thu Aug 03 2023 - 09:11:15 EST

> -----Original Message-----
> From: Johannes Zink <j.zink@xxxxxxxxxxxxxx>
> Sent: Thursday, August 3, 2023 1:36 AM
> To: Shenwei Wang <>; Russell King
> <linux@xxxxxxxxxxxxxxx>; David S. Miller <davem@xxxxxxxxxxxxx>; Eric
> Dumazet <edumazet@xxxxxxxxxx>; Jakub Kicinski <kuba@xxxxxxxxxx>; Paolo
> Abeni <pabeni@xxxxxxxxxx>; Maxime Coquelin
> <mcoquelin.stm32@xxxxxxxxx>; Shawn Guo <shawnguo@xxxxxxxxxx>; Sascha
> Hauer <s.hauer@xxxxxxxxxxxxxx>; Neil Armstrong <neil.armstrong@xxxxxxxxxx>;
> Kevin Hilman <khilman@xxxxxxxxxxxx>; Vinod Koul <vkoul@xxxxxxxxxx>; Chen-
> Yu Tsai <wens@xxxxxxxx>; Jernej Skrabec <jernej.skrabec@xxxxxxxxx>; Samuel
> Holland <samuel@xxxxxxxxxxxx>
> Cc: Giuseppe Cavallaro <peppe.cavallaro@xxxxxx>; Alexandre Torgue
> <alexandre.torgue@xxxxxxxxxxx>; Jose Abreu <joabreu@xxxxxxxxxxxx>;
> Pengutronix Kernel Team <kernel@xxxxxxxxxxxxxx>; Fabio Estevam
> <festevam@xxxxxxxxx>; dl-linux-imx <linux-imx@xxxxxxx>; Jerome Brunet
> <jbrunet@xxxxxxxxxxxx>; Martin Blumenstingl
> <martin.blumenstingl@xxxxxxxxxxxxxx>; Bhupesh Sharma
> <bhupesh.sharma@xxxxxxxxxx>; Nobuhiro Iwamatsu
> <nobuhiro1.iwamatsu@xxxxxxxxxxxxx>; Simon Horman
> > It has the general fix_speed function there named imx_dwmac_fix_speed.
> > This one is the special for this mx93 fix.
> I think I might have misunderstood your last statement or I failed to express my
> point. If you need to replace the dwmac_fix_speed() on mx93, because this SoC
> implementation requires doing so (the usual reason for doing something like this
> is something like reset quirks because of screwed up IP Core integration), then
> your approach is imho valid.
> But if I got your last comment right, your changes should apply to EQOS MAC in
> general (but you want to only enable it for mx93 at the moment). In this case
> this quirk will later be as the fix_mac_speed function for other hardware as well,
> in which case the name ..._mx93 is misleading, and imho rather a descriptive
> name should be used (i.e. have the name describe what it does rather than for
> what hardware it is implemented).

The idea of supporting the SJA1105 is general, but the implementation depends on the
specific SoC. This patch provides the implementation for the MX93 SoC. To support the
MX8x SoCs, the implementation would need to be rewritten based on the current state
of the dwmac-imx driver.

I agree the function name is somewhat ugly. Maybe a better name could be:

The assumption is that the process of pausing the clock can still be considered part of fixing the speed.


> Except if the maintainers have a strong opinion that the ..._mx93 suffix version
> is exactly how you should proceed...
> Best regards
> Johannes
> >
> > Thanks,
> > Shenwei
> > [snip]
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