ASoC: wm_adsp: Fix dma-unsafe read of scratch registers

BugLink: https://bugs.launchpad.net/bugs/1837161
[ Upstream commit 20e00db2f59bdddf8a8e241473ef8be94631d3ae ]

Stack memory isn't DMA-safe so it isn't safe to use either
regmap_raw_read or regmap_bulk_read to read into stack memory.

The two functions to read the scratch registers were using
stack memory and regmap_raw_read. It's not worth allocating
memory just for this trivial read, and it isn't time-critical.
A simple regmap_read for each register is sufficient.

Signed-off-by: Richard Fitzgerald <rf@opensource.cirrus.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>

diff --git a/sound/soc/codecs/wm_adsp.c b/sound/soc/codecs/wm_adsp.c
index 989d093abda7e6c25c7f812e62596e0005d74d42..67330b6ab204c3ff7c5f0322195bc1ea594e2896 100644 (file)
--- a/sound/soc/codecs/wm_adsp.c
+++ b/sound/soc/codecs/wm_adsp.c
@@ -787,38 +787,41 @@ static unsigned int wm_adsp_region_to_reg(struct wm_adsp_region const *mem,
 
 static void wm_adsp2_show_fw_status(struct wm_adsp *dsp)
 {
-       u16 scratch[4];
+       unsigned int scratch[4];
+       unsigned int addr = dsp->base + ADSP2_SCRATCH0;
+       unsigned int i;
        int ret;
 
-       ret = regmap_raw_read(dsp->regmap, dsp->base + ADSP2_SCRATCH0,
-                               scratch, sizeof(scratch));
-       if (ret) {
-               adsp_err(dsp, "Failed to read SCRATCH regs: %d\n", ret);
-               return;
+       for (i = 0; i < ARRAY_SIZE(scratch); ++i) {
+               ret = regmap_read(dsp->regmap, addr + i, &scratch[i]);
+               if (ret) {
+                       adsp_err(dsp, "Failed to read SCRATCH%u: %d\n", i, ret);
+                       return;
+               }
        }
 
        adsp_dbg(dsp, "FW SCRATCH 0:0x%x 1:0x%x 2:0x%x 3:0x%x\n",
-                be16_to_cpu(scratch[0]),
-                be16_to_cpu(scratch[1]),
-                be16_to_cpu(scratch[2]),
-                be16_to_cpu(scratch[3]));
+                scratch[0], scratch[1], scratch[2], scratch[3]);
 }
 
 static void wm_adsp2v2_show_fw_status(struct wm_adsp *dsp)
 {
-       u32 scratch[2];
+       unsigned int scratch[2];
        int ret;
 
-       ret = regmap_raw_read(dsp->regmap, dsp->base + ADSP2V2_SCRATCH0_1,
-                             scratch, sizeof(scratch));
-
+       ret = regmap_read(dsp->regmap, dsp->base + ADSP2V2_SCRATCH0_1,
+                         &scratch[0]);
        if (ret) {
-               adsp_err(dsp, "Failed to read SCRATCH regs: %d\n", ret);
+               adsp_err(dsp, "Failed to read SCRATCH0_1: %d\n", ret);
                return;
        }
 
-       scratch[0] = be32_to_cpu(scratch[0]);
-       scratch[1] = be32_to_cpu(scratch[1]);
+       ret = regmap_read(dsp->regmap, dsp->base + ADSP2V2_SCRATCH2_3,
+                         &scratch[1]);
+       if (ret) {
+               adsp_err(dsp, "Failed to read SCRATCH2_3: %d\n", ret);
+               return;
+       }
 
        adsp_dbg(dsp, "FW SCRATCH 0:0x%x 1:0x%x 2:0x%x 3:0x%x\n",
                 scratch[0] & 0xFFFF,