Re: [PATCH -next] dmaengine: apple-admac: Fix build on 32-bit/non-LPAE platforms

From: Vinod Koul
Date: Thu Jun 16 2022 - 09:45:03 EST


Hello Geert,

On 14-06-22, 09:49, Geert Uytterhoeven wrote:
> If CONFIG_PHYS_ADDR_T_64BIT is not set:
>
> drivers/dma/apple-admac.c: In function ‘admac_cyclic_write_one_desc’:
> drivers/dma/apple-admac.c:213:22: error: right shift count >= width of type [-Werror=shift-count-overflow]
> 213 | writel_relaxed(addr >> 32, ad->base + REG_DESC_WRITE(channo));
> | ^~
>
> Fix this by using the {low,upp}er_32_bits() helper macros to obtain the
> address parts.

This changelog is good, but patch title needs update. We should never
reflect the effect of change, but describe the change in patch...

Maybe "dmaengine: apple-admac: use {lower|upper}_32_bits() for
extracting address" would be a better patch title...

Thanks

>
> Reported-by: noreply@xxxxxxxxxxxxxx
> Fixes: b127315d9a78c011 ("dmaengine: apple-admac: Add Apple ADMAC driver")
> Signed-off-by: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx>
> ---
> drivers/dma/apple-admac.c | 8 ++++----
> 1 file changed, 4 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/dma/apple-admac.c b/drivers/dma/apple-admac.c
> index c502f8c3aca79be1..d1f74a3aa999d773 100644
> --- a/drivers/dma/apple-admac.c
> +++ b/drivers/dma/apple-admac.c
> @@ -209,10 +209,10 @@ static void admac_cyclic_write_one_desc(struct admac_data *ad, int channo,
> dev_dbg(ad->dev, "ch%d descriptor: addr=0x%pad len=0x%zx flags=0x%lx\n",
> channo, &addr, tx->period_len, FLAG_DESC_NOTIFY);
>
> - writel_relaxed(addr, ad->base + REG_DESC_WRITE(channo));
> - writel_relaxed(addr >> 32, ad->base + REG_DESC_WRITE(channo));
> - writel_relaxed(tx->period_len, ad->base + REG_DESC_WRITE(channo));
> - writel_relaxed(FLAG_DESC_NOTIFY, ad->base + REG_DESC_WRITE(channo));
> + writel_relaxed(lower_32_bits(addr), ad->base + REG_DESC_WRITE(channo));
> + writel_relaxed(upper_32_bits(addr), ad->base + REG_DESC_WRITE(channo));
> + writel_relaxed(tx->period_len, ad->base + REG_DESC_WRITE(channo));
> + writel_relaxed(FLAG_DESC_NOTIFY, ad->base + REG_DESC_WRITE(channo));
>
> tx->submitted_pos += tx->period_len;
> tx->submitted_pos %= 2 * tx->buf_len;
> --
> 2.25.1

--
~Vinod