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Fixes: 4b565ca5a2cb ("drm/msm: Add A6XX device support") Signed-off-by: Akhil P Oommen --- drivers/gpu/drm/msm/adreno/a6xx_hfi.c | 14 ++++++++++---- 1 file changed, 10 insertions(+), 4 deletions(-) diff --git a/drivers/gpu/drm/msm/adreno/a6xx_hfi.c b/drivers/gpu/drm/msm/ad= reno/a6xx_hfi.c index 53cfdf4e6c34..4f5dbf46132b 100644 --- a/drivers/gpu/drm/msm/adreno/a6xx_hfi.c +++ b/drivers/gpu/drm/msm/adreno/a6xx_hfi.c @@ -34,7 +34,7 @@ static int a6xx_hfi_queue_read(struct a6xx_gmu *gmu, struct a6xx_hfi_queue_header *header =3D queue->header; u32 i, hdr, index =3D header->read_index; =20 - if (header->read_index =3D=3D header->write_index) { + if (header->read_index =3D=3D READ_ONCE(header->write_index)) { header->rx_request =3D 1; return 0; } @@ -62,7 +62,10 @@ static int a6xx_hfi_queue_read(struct a6xx_gmu *gmu, if (!gmu->legacy) index =3D ALIGN(index, 4) % header->size; =20 - header->read_index =3D index; + /* Ensure all memory operations are complete before updating the read ind= ex */ + dma_mb(); + + WRITE_ONCE(header->read_index, index); return HFI_HEADER_SIZE(hdr); } =20 @@ -74,7 +77,7 @@ static int a6xx_hfi_queue_write(struct a6xx_gmu *gmu, =20 spin_lock(&queue->lock); =20 - space =3D CIRC_SPACE(header->write_index, header->read_index, + space =3D CIRC_SPACE(header->write_index, READ_ONCE(header->read_index), header->size); if (space < dwords) { header->dropped++; @@ -95,7 +98,10 @@ static int a6xx_hfi_queue_write(struct a6xx_gmu *gmu, queue->data[index] =3D 0xfafafafa; } =20 - header->write_index =3D index; + /* Ensure all memory operations are complete before updating the write in= dex */ + dma_mb(); + + WRITE_ONCE(header->write_index, index); spin_unlock(&queue->lock); =20 gmu_write(gmu, REG_A6XX_GMU_HOST2GMU_INTR_SET, 0x01); --=20 2.51.0