| From dcf08d0f8f09081b16f69071dd55d51d5e964e84 Mon Sep 17 00:00:00 2001 |
| From: Daniel Baluta <daniel.baluta@nxp.com> |
| Date: Fri, 20 Dec 2019 11:05:31 -0600 |
| Subject: ASoC: SOF: imx8: Fix dsp_box offset |
| |
| From: Daniel Baluta <daniel.baluta@nxp.com> |
| |
| commit dcf08d0f8f09081b16f69071dd55d51d5e964e84 upstream. |
| |
| dsp_box is used to keep DSP initiated messages. The value of dsp_offset |
| is set by the DSP with the first message, so we need a way to bootstrap |
| it in order to get the first message. |
| |
| We do this by setting the correct default dsp_box offset which on i.MX8 |
| is not zero. |
| |
| Very interesting is why it has worked until now. |
| |
| On i.MX8, DSP communicates with ARM core using a shared SDRAM memory |
| area. Actually, there are two shared areas: |
| * SDRAM0 - starting at 0x92400000, size 0x800000 |
| * SDRAM1 - starting at 0x92C00000, size 0x800000 |
| |
| SDRAM0 keeps the data sections, starting with .rodata. By chance |
| fw_ready structure was placed at the beginning of .rodata. |
| |
| dsp_box_base is defined as SDRAM0 + dsp_box_offset and it is placed |
| at the beginning of SDRAM1 (dsp_box_offset should be 0x800000). But |
| because it is zero initialized by default it points to SDRAM0 where |
| by chance the fw_ready was placed in the SOF firmware. |
| |
| Anyhow, SOF commit 7466bee378dd811b ("clk: make freq arrays constant") |
| fw_ready is no longer at the beginning of SDRAM0 and everything shows |
| how lucky we were until now. |
| |
| Fix this by properly setting the default dsp_box offset. |
| |
| Fixes: 202acc565a1f050 ("ASoC: SOF: imx: Add i.MX8 HW support") |
| Signed-off-by: Daniel Baluta <daniel.baluta@nxp.com> |
| Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com> |
| Link: https://lore.kernel.org/r/20191220170531.10423-1-pierre-louis.bossart@linux.intel.com |
| Signed-off-by: Mark Brown <broonie@kernel.org> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| |
| --- |
| sound/soc/sof/imx/imx8.c | 3 +++ |
| 1 file changed, 3 insertions(+) |
| |
| --- a/sound/soc/sof/imx/imx8.c |
| +++ b/sound/soc/sof/imx/imx8.c |
| @@ -304,6 +304,9 @@ static int imx8_probe(struct snd_sof_dev |
| } |
| sdev->mailbox_bar = SOF_FW_BLK_TYPE_SRAM; |
| |
| + /* set default mailbox offset for FW ready message */ |
| + sdev->dsp_box.offset = MBOX_OFFSET; |
| + |
| return 0; |
| |
| exit_pdev_unregister: |
