Re: [PATCH -next] spi: Fix double IDR allocation with DT aliases

Hi Greg,

On Tue, Aug 21, 2018 at 3:40 PM Greg KH [off-list ref] wrote:

On Tue, Aug 21, 2018 at 11:53:03AM +0200, Geert Uytterhoeven wrote:

quoted

If the SPI bus number is provided by a DT alias, idr_alloc() is called
twice, leading to:

    WARNING: CPU: 1 PID: 1 at drivers/spi/spi.c:2179 spi_register_controller+0x11c/0x5d8
    couldn't get idr

Fix this by moving the handling of fixed SPI bus numbers up, before the
DT handling code fills in ctlr->bus_num.

Fixes: 1a4327fbf4554d5b ("spi: fix IDR collision on systems with both fixed and dynamic SPI bus numbers")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
---
Seen on e.g. r8a7791/koelsch, breaking both RSPI and MSIOF.
---
 drivers/spi/spi.c | 22 +++++++++++-----------
 1 file changed, 11 insertions(+), 11 deletions(-)

<formletter>

This is not the correct way to submit patches for inclusion in the
stable kernel tree.  Please read:
    https://www.kernel.org/doc/html/latest/process/stable-kernel-rules.html
for how to do this properly.

</formletter>

I know.

I only CCed stable because the acceptance email for the original patch was
CCed to stable, and I wanted to prevent that one from being backported early.

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