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Re: [PATCH 08/22] hw/sd: ssi-sd: Support multiple block read (CMD18)
From: |
Alistair Francis |
Subject: |
Re: [PATCH 08/22] hw/sd: ssi-sd: Support multiple block read (CMD18) |
Date: |
Wed, 13 Jan 2021 08:59:35 -0800 |
On Thu, Dec 31, 2020 at 3:41 AM Bin Meng <bmeng.cn@gmail.com> wrote:
>
> From: Bin Meng <bin.meng@windriver.com>
>
> In the case of a multiple block read operation every transfered
> block has its suffix of CRC16. Update the state machine logic to
> handle multiple block read.
>
> This also fixed the wrong command index for STOP_TRANSMISSION,
> the required command to interupt the multiple block read command,
> in the old codes. It should be CMD12 (0x4c), not CMD13 (0x4d).
>
> Signed-off-by: Bin Meng <bin.meng@windriver.com>
Acked-by: Alistair Francis <alistair.francis@wdc.com>
Alistair
> ---
>
> hw/sd/ssi-sd.c | 15 ++++++++++++---
> 1 file changed, 12 insertions(+), 3 deletions(-)
>
> diff --git a/hw/sd/ssi-sd.c b/hw/sd/ssi-sd.c
> index 10b0ac2eaf..889260bd8f 100644
> --- a/hw/sd/ssi-sd.c
> +++ b/hw/sd/ssi-sd.c
> @@ -51,6 +51,7 @@ struct ssi_sd_state {
> uint8_t cmdarg[4];
> uint8_t response[5];
> uint16_t crc16;
> + int32_t read_bytes;
> int32_t arglen;
> int32_t response_pos;
> int32_t stopping;
> @@ -82,7 +83,7 @@ static uint32_t ssi_sd_transfer(SSIPeripheral *dev,
> uint32_t val)
> ssi_sd_state *s = SSI_SD(dev);
>
> /* Special case: allow CMD12 (STOP TRANSMISSION) while reading data. */
> - if (s->mode == SSI_SD_DATA_READ && val == 0x4d) {
> + if (s->mode == SSI_SD_DATA_READ && val == 0x4c) {
> s->mode = SSI_SD_CMD;
> /* There must be at least one byte delay before the card responds.
> */
> s->stopping = 1;
> @@ -200,8 +201,9 @@ static uint32_t ssi_sd_transfer(SSIPeripheral *dev,
> uint32_t val)
> return 0xfe;
> case SSI_SD_DATA_READ:
> val = sdbus_read_byte(&s->sdbus);
> + s->read_bytes++;
> s->crc16 = crc_ccitt_false(s->crc16, (uint8_t *)&val, 1);
> - if (!sdbus_data_ready(&s->sdbus)) {
> + if (!sdbus_data_ready(&s->sdbus) || s->read_bytes == 512) {
> DPRINTF("Data read end\n");
> s->mode = SSI_SD_DATA_CRC16;
> }
> @@ -212,7 +214,12 @@ static uint32_t ssi_sd_transfer(SSIPeripheral *dev,
> uint32_t val)
> s->response_pos++;
> if (s->response_pos == 2) {
> DPRINTF("CRC16 read end\n");
> - s->mode = SSI_SD_CMD;
> + if (s->read_bytes == 512 && s->cmd != 17) {
> + s->mode = SSI_SD_DATA_START;
> + } else {
> + s->mode = SSI_SD_CMD;
> + }
> + s->read_bytes = 0;
> s->response_pos = 0;
> }
> return val;
> @@ -252,6 +259,7 @@ static const VMStateDescription vmstate_ssi_sd = {
> VMSTATE_UINT8_ARRAY(cmdarg, ssi_sd_state, 4),
> VMSTATE_UINT8_ARRAY(response, ssi_sd_state, 5),
> VMSTATE_UINT16(crc16, ssi_sd_state),
> + VMSTATE_INT32(read_bytes, ssi_sd_state),
> VMSTATE_INT32(arglen, ssi_sd_state),
> VMSTATE_INT32(response_pos, ssi_sd_state),
> VMSTATE_INT32(stopping, ssi_sd_state),
> @@ -304,6 +312,7 @@ static void ssi_sd_reset(DeviceState *dev)
> memset(s->cmdarg, 0, sizeof(s->cmdarg));
> memset(s->response, 0, sizeof(s->response));
> s->crc16 = 0;
> + s->read_bytes = 0;
> s->arglen = 0;
> s->response_pos = 0;
> s->stopping = 0;
> --
> 2.25.1
>
>
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