Currently, this local RAM is not accessible from the CPU.
If the CPU tries to access it, then the CPU will hang.

Remoteproc may try to use it when it load a firmware
that has some sections in the local RAM.
This workarounds the issue by skiping this section.

Signed-off-by: Alexandre Bailon <abai...@baylibre.com>
---
 drivers/remoteproc/mtk_apu_rproc.c | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/drivers/remoteproc/mtk_apu_rproc.c 
b/drivers/remoteproc/mtk_apu_rproc.c
index 565b3adca5de..e16d3258a785 100644
--- a/drivers/remoteproc/mtk_apu_rproc.c
+++ b/drivers/remoteproc/mtk_apu_rproc.c
@@ -57,6 +57,9 @@
 #define CORE_DEFAULT2_SPIDEN                   BIT(0)
 #define CORE_XTENSA_ALTRESETVEC                        (0x000001F8)
 
+#define DRAM0_START                            (0x7ff00000)
+#define IRAM0_END                              (0x7ff80000)
+
 struct mtk_vpu_rproc {
        struct device *dev;
        struct rproc *rproc;
@@ -139,6 +142,7 @@ static void mtk_vpu_rproc_kick(struct rproc *rproc, int 
vqid)
 
 int mtk_vpu_elf_sanity_check(struct rproc *rproc, const struct firmware *fw)
 {
+       struct mtk_vpu_rproc *vpu_rproc = rproc->priv;
        const u8 *elf_data = fw->data;
        struct elf32_hdr *ehdr;
        struct elf32_phdr *phdr;
@@ -156,6 +160,16 @@ int mtk_vpu_elf_sanity_check(struct rproc *rproc, const 
struct firmware *fw)
                /* Remove empty PT_LOAD section */
                if (phdr->p_type == PT_LOAD && !phdr->p_paddr)
                        phdr->p_type = PT_NULL;
+               /*
+                * Workaround: Currently, the CPU can't access to the APU
+                * local RAM. This removes the local RAM section from the
+                * firmware. Please note that may cause some issues.
+                */
+               if (phdr->p_paddr >= DRAM0_START && phdr->p_paddr < IRAM0_END) {
+                       dev_warn_once(vpu_rproc->dev,
+                                     "Skipping the APU local RAM section\n");
+                       phdr->p_type = PT_NULL;
+               }
        }
 
        return 0;
-- 
2.26.2

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