mmc_spi: Recover from CRC errors for r/w operation over SPI. (061c6c84) · Commits · 戴 / test

drivers/mmc/host/mmc_spi.c

+21 −0

Original line number	Diff line number	Diff line
		@@ -1055,6 +1055,8 @@ static void mmc_spi_request(struct mmc_host mmc, struct mmc_request mrq)
		{
		struct mmc_spi_host *host = mmc_priv(mmc);
		int status = -EINVAL;
		int crc_retry = 5;
		struct mmc_command stop;

		#ifdef DEBUG
		/* MMC core and layered drivers MUST issue SPI-aware commands */
		@@ -1087,10 +1089,29 @@ static void mmc_spi_request(struct mmc_host mmc, struct mmc_request mrq)
		/* request exclusive bus access */
		spi_bus_lock(host->spi->master);

		crc_recover:
		/* issue command; then optionally data and stop */
		status = mmc_spi_command_send(host, mrq, mrq->cmd, mrq->data != NULL);
		if (status == 0 && mrq->data) {
		mmc_spi_data_do(host, mrq->cmd, mrq->data, mrq->data->blksz);

		/*
		* The SPI bus is not always reliable for large data transfers.
		* If an occasional crc error is reported by the SD device with
		* data read/write over SPI, it may be recovered by repeating
		* the last SD command again. The retry count is set to 5 to
		* ensure the driver passes stress tests.
		*/
		if (mrq->data->error == -EILSEQ && crc_retry) {
		stop.opcode = MMC_STOP_TRANSMISSION;
		stop.arg = 0;
		stop.flags = MMC_RSP_SPI_R1B \| MMC_RSP_R1B \| MMC_CMD_AC;
		status = mmc_spi_command_send(host, mrq, &stop, 0);
		crc_retry--;
		mrq->data->error = 0;
		goto crc_recover;
		}

		if (mrq->stop)
		status = mmc_spi_command_send(host, mrq, mrq->stop, 0);
		else