Messages in this thread | | | From | Geert Uytterhoeven <> | Date | Tue, 19 Sep 2023 11:27:04 +0200 | Subject | Re: [PATCH RFT 1/2] i2c: rcar: reset controller is mandatory for Gen3+ |
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Hi Wolfram,
On Tue, Sep 19, 2023 at 11:19 AM Wolfram Sang <wsa+renesas@sang-engineering.com> wrote: > > > + ret = reset_control_status(priv->rstc); > > > + if (ret < 0) > > > + return ret; > > > > This is a pre-existing check, but do you really need it? > > This condition will be true if the reset is still asserted, which > > could happen due to some glitch, or force-booting into a new kernel > > using kexec. And AFAIUI, that should be resolved by the call to > > rcar_i2c_do_reset() above. > > This check is needed to ensure reset_control_status() really works > because we need it in rcar_i2c_do_reset(). From the docs: > > "reset_control_status - returns a negative errno if not supported,..." > > The code only checks for that, not for the status of the reset line.
Right, I missed the negative. I don't think this can fail on R-Car Gen2+ (using the CPG/MSSR driver) if devm_reset_control_get_exclusive() succeeded, but it's prudent, in case the block is every reused on a different SoC family.
Gr{oetje,eeting}s,
Geert
-- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org
In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds
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