Messages in this thread | | | Date | Thu, 30 Mar 2023 14:45:18 +0200 | From | "Arnd Bergmann" <> | Subject | Re: [PATCH] mfd: syscon: Use of_io_request_and_map() for IO mapping |
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On Thu, Mar 30, 2023, at 13:42, Lee Jones wrote: > On Mon, 20 Mar 2023, Loic Poulain wrote: > >> Use of_io_request_and_map() instead of of_iomap() so that the >> region is reserved and protected, i.e reported in /proc/iomem >> and not accessible from user side (CONFIG_IO_STRICT_DEVMEM). >> >> Signed-off-by: Loic Poulain <loic.poulain@linaro.org> >> --- >> drivers/mfd/syscon.c | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> diff --git a/drivers/mfd/syscon.c b/drivers/mfd/syscon.c >> index bdb2ce7ff03b..7e6d4edda118 100644 >> --- a/drivers/mfd/syscon.c >> +++ b/drivers/mfd/syscon.c >> @@ -60,7 +60,7 @@ static struct syscon *of_syscon_register(struct device_node *np, bool check_clk) >> goto err_map; >> } >> >> - base = of_iomap(np, 0); >> + base = of_io_request_and_map(np, 0, NULL); >> if (!base) { >> ret = -ENOMEM; >> goto err_map; > > Looks sane though. > > Arnd, do you have an opinion?
Thanks for pinging me. I would indeed expect this to cause problems, as syscon mappings are likely to be used in a way that is not entirely clean, with other devices defining overlapping ranges.
For any other driver, the change makes a lot of sense after checking the DT file, but for syscon in particular I don't think it's even realistic to check all users.
Arnd
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