From: Daniel Baluta daniel.baluta@nxp.com
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 --- sound/soc/sof/imx/imx8.c | 3 +++ 1 file changed, 3 insertions(+)
diff --git a/sound/soc/sof/imx/imx8.c b/sound/soc/sof/imx/imx8.c index cfefcfd92798..dca85cf07ffa 100644 --- 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) } 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: