On Tue, Dec 10, 2024 at 6:10 PM Claudiu <claudiu.beznea@xxxxxxxxx> wrote:
> From: Claudiu Beznea <claudiu.beznea.uj@xxxxxxxxxxxxxx>
>
> The stop trigger invokes rz_ssi_stop() and rz_ssi_stream_quit().
> - The purpose of rz_ssi_stop() is to disable TX/RX, terminate DMA
> transactions, and set the controller to idle.
> - The purpose of rz_ssi_stream_quit() is to reset the substream-specific
> software data by setting strm->running and strm->substream appropriately.
>
> The function rz_ssi_is_stream_running() checks if both strm->substream and
> strm->running are valid and returns true if so. Its implementation is as
> follows:
>
> static inline bool rz_ssi_is_stream_running(struct rz_ssi_stream *strm)
> {
> return strm->substream && strm->running;
> }
>
> When the controller is configured in full-duplex mode (with both playback
> and capture active), the rz_ssi_stop() function does not modify the
> controller settings when called for the first substream in the full-duplex
> setup. Instead, it simply sets strm->running = 0 and returns if the
> companion substream is still running. The following code illustrates this:
>
> static int rz_ssi_stop(struct rz_ssi_priv *ssi, struct rz_ssi_stream *strm)
> {
> strm->running = 0;
>
> if (rz_ssi_is_stream_running(&ssi->playback) ||
> rz_ssi_is_stream_running(&ssi->capture))
> return 0;
>
> // ...
> }
>
> The controller settings, along with the DMA termination (for the last
> stopped substream), are only applied when the last substream in the
> full-duplex setup is stopped.
>
> While applying the controller settings only when the last substream stops
> is not problematic, terminating the DMA operations for only one substream
> causes failures when starting and stopping full-duplex operations multiple
> times in a loop.
>
> To address this issue, call dmaengine_terminate_async() for both substreams
> involved in the full-duplex setup when the last substream in the setup is
> stopped.
>
> Fixes: 4f8cd05a4305 ("ASoC: sh: rz-ssi: Add full duplex support")
> Cc: stable@xxxxxxxxxxxxxxx
> Reviewed-by: Biju Das <biju.das.jz@xxxxxxxxxxxxxx>
> Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@xxxxxxxxxxxxxx>
> ---
>
> Changes in v4:
> - updated patch description
Reviewed-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
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
