Il 14/03/22 12:18, Tinghan Shen ha scritto:
The definition of L1TCM_SRAM_PDN bits on mt8195 is different to mt8192.
L1TCM_SRAM_PDN bits[3:0] control the power of mt8195 L1TCM SRAM.
L1TCM_SRAM_PDN bits[7:4] control the access path to EMI for SCP.
These bits have to be powered on to allow EMI access for SCP.
Bits[7:4] also affect audio DSP because audio DSP and SCP are
placed on the same hardware bus. If SCP cannot access EMI, audio DSP is
blocked too.
L1TCM_SRAM_PDN bits[31:8] are not used.
This fix removes modification of bits[7:4] when power on/off mt8195 SCP
L1TCM. It's because the modification introduces a short period of time
blocking audio DSP to access EMI. This was not a problem until we have
to load both SCP module and audio DSP module. audio DSP needs to access
EMI because it has source/data on DRAM. Audio DSP will have unexpected
behavior when it accesses EMI and the SCP driver blocks the EMI path at
the same time.
Signed-off-by: Tinghan Shen <tinghan.shen@xxxxxxxxxxxx>
Hello Tinghan,
I'm sorry, but in the last review I forgot to mention that you should
really add a Fixes tag to this commit, since this is.. a fix.
This is the tag that you should use:
Fixes: 79111df414fc ("remoteproc: mediatek: Support mt8195 scp")
After adding that,
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@xxxxxxxxxxxxx>
---
v3: fix build error
v2: apply comments about macro definition and function calls
---
drivers/remoteproc/mtk_common.h | 2 +
drivers/remoteproc/mtk_scp.c | 67 +++++++++++++++++++++++++--------
2 files changed, 53 insertions(+), 16 deletions(-)
