Re: [PATCH] spi: rzv2h-rspi: fix incorrect readl() accessor for 8-bit RX path

[Felix Gu]

Hi Geert,

On Mon, Jun 8, 2026 at 3:55 PM Geert Uytterhoeven <geert@xxxxxxxxxxxxxx> wrote:
>
> Hi Felix,
>
> On Fri, 5 Jun 2026 at 17:26, Felix Gu <ustc.gu@xxxxxxxxx> wrote:
> >
> > Fixes: 8b61c8919dff ("spi: Add driver for the RZ/V2H(P) RSPI IP")
> > Signed-off-by: Felix Gu <ustc.gu@xxxxxxxxx>
>
> Thanks for your patch!
>
>
> According to Chapter 7.5 Serial Peripheral Interface (RSPI) Subsection
> 7.5.2.1 List of Registers, the SPI Data Register supports access sizes
> of 8, 16, and 32 bits.
>
> However, the "Access Size [bits]*1" column header has a foot note:
>
>     "Note 1.  The read access size is fixed at 32 bits."
>
> Hence that means the rzv2h_rspi_rx_u8() function as generated by the
> RZV2H_RSPI_RX() macro is correct, but rzv2h_rspi_rx_u16() is not?
>
> Also, readw() in rzv2h_rx_irq_handler() is wrong, too?
>
Thanks for the detailed explanation.
I didn't check the reference, just thought it's a little weird here.

Although the column header has a footnote to indicate the access
size is fixed at 32bits.
But in 7.5.2.2 register description, it specifies that for registers like
SPDR, SPCR, SPSCR, SPCMD, SPDCR2, SPSSR, their access
size are fixed at 32bits, but for SPSR, there is no footnote to specify
the access size.
And SPSR is 0x52, readl on the register cause alignment issue?


Best regards,
Felix



> Gr{oetje,eeting}s,
>
>                         Geert
>
> --
> Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx
>
> 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