On Thu, Dec 31, 2020 at 3:38 AM Bin Meng <bmeng...@gmail.com> wrote:
>
> From: Bin Meng <bin.m...@windriver.com>
>
> Per the SD spec, a valid data block is suffixed with a 16-bit CRC
> generated by the standard CCITT polynomial x16+x12+x5+1. This part
> is currently missing in the ssi-sd state machine. Without it, all
> data block transfer fails in guest software because the expected
> CRC16 is missing on the data out line.
>
> Fixes: 775616c3ae8c ("Partial SD card SPI mode support")
> Signed-off-by: Bin Meng <bin.m...@windriver.com>
Acked-by: Alistair Francis <alistair.fran...@wdc.com>
Alistair
> ---
>
> hw/sd/ssi-sd.c | 17 +++++++++++++++++
> 1 file changed, 17 insertions(+)
>
> diff --git a/hw/sd/ssi-sd.c b/hw/sd/ssi-sd.c
> index 228ce4ddc7..10b0ac2eaf 100644
> --- a/hw/sd/ssi-sd.c
> +++ b/hw/sd/ssi-sd.c
> @@ -17,6 +17,7 @@
> #include "hw/qdev-properties.h"
> #include "hw/sd/sd.h"
> #include "qapi/error.h"
> +#include "qemu/crc-ccitt.h"
> #include "qemu/module.h"
> #include "qom/object.h"
>
> @@ -40,6 +41,7 @@ typedef enum {
> SSI_SD_RESPONSE,
> SSI_SD_DATA_START,
> SSI_SD_DATA_READ,
> + SSI_SD_DATA_CRC16,
> } ssi_sd_mode;
>
> struct ssi_sd_state {
> @@ -48,6 +50,7 @@ struct ssi_sd_state {
> int cmd;
> uint8_t cmdarg[4];
> uint8_t response[5];
> + uint16_t crc16;
> int32_t arglen;
> int32_t response_pos;
> int32_t stopping;
> @@ -193,12 +196,24 @@ static uint32_t ssi_sd_transfer(SSIPeripheral *dev,
> uint32_t val)
> case SSI_SD_DATA_START:
> DPRINTF("Start read block\n");
> s->mode = SSI_SD_DATA_READ;
> + s->response_pos = 0;
> return 0xfe;
> case SSI_SD_DATA_READ:
> val = sdbus_read_byte(&s->sdbus);
> + s->crc16 = crc_ccitt_false(s->crc16, (uint8_t *)&val, 1);
> if (!sdbus_data_ready(&s->sdbus)) {
> DPRINTF("Data read end\n");
> + s->mode = SSI_SD_DATA_CRC16;
> + }
> + return val;
> + case SSI_SD_DATA_CRC16:
> + val = (s->crc16 & 0xff00) >> 8;
> + s->crc16 <<= 8;
> + s->response_pos++;
> + if (s->response_pos == 2) {
> + DPRINTF("CRC16 read end\n");
> s->mode = SSI_SD_CMD;
> + s->response_pos = 0;
> }
> return val;
> }
> @@ -236,6 +251,7 @@ static const VMStateDescription vmstate_ssi_sd = {
> VMSTATE_INT32(cmd, ssi_sd_state),
> VMSTATE_UINT8_ARRAY(cmdarg, ssi_sd_state, 4),
> VMSTATE_UINT8_ARRAY(response, ssi_sd_state, 5),
> + VMSTATE_UINT16(crc16, ssi_sd_state),
> VMSTATE_INT32(arglen, ssi_sd_state),
> VMSTATE_INT32(response_pos, ssi_sd_state),
> VMSTATE_INT32(stopping, ssi_sd_state),
> @@ -287,6 +303,7 @@ static void ssi_sd_reset(DeviceState *dev)
> s->cmd = 0;
> memset(s->cmdarg, 0, sizeof(s->cmdarg));
> memset(s->response, 0, sizeof(s->response));
> + s->crc16 = 0;
> s->arglen = 0;
> s->response_pos = 0;
> s->stopping = 0;
> --
> 2.25.1
>
>
