mmc: sdhci: Wait for SDHCI_INT_DATA_END when transferring.

sdhci_transfer_data() function transfers the blocks passed up to the
number of blocks defined in mmc_data, but returns immediately once all
the blocks are transferred, even if the loop exit condition is not met
(bit SDHCI_INT_DATA_END set in the STATUS word).

When doing multiple writes to mmc, returning right after the last block
is transferred can cause the write to fail when sending the
MMC_CMD_STOP_TRANSMISSION command right after the
MMC_CMD_WRITE_MULTIPLE_BLOCK command, leaving the mmc driver in an
unconsistent state until reboot. This error was observed in the rpi3
board.

This patch waits for the SDHCI_INT_DATA_END bit to be set even after
sending all the blocks.

Test: Reliably wrote 2GiB of data to mmc in a rpi3.

Signed-off-by: Alex Deymo <deymo@google.com>
Reviewed-by: Simon Glass <sjg@chromium.org>

diff --git a/drivers/mmc/sdhci.c b/drivers/mmc/sdhci.c
index c94d58db65c70ee8b32cd64e79ebd1b8f44dc262..b745977b3fba17dcd2299dfde73c47688b3835ae 100644 (file)
--- a/drivers/mmc/sdhci.c
+++ b/drivers/mmc/sdhci.c
@@ -72,6 +72,7 @@ static int sdhci_transfer_data(struct sdhci_host *host, struct mmc_data *data,
                                unsigned int start_addr)
 {
        unsigned int stat, rdy, mask, timeout, block = 0;
+       bool transfer_done = false;
 #ifdef CONFIG_MMC_SDHCI_SDMA
        unsigned char ctrl;
        ctrl = sdhci_readb(host, SDHCI_HOST_CONTROL);
@@ -89,17 +90,23 @@ static int sdhci_transfer_data(struct sdhci_host *host, struct mmc_data *data,
                               __func__, stat);
                        return -EIO;
                }
-               if (stat & rdy) {
+               if (!transfer_done && (stat & rdy)) {
                        if (!(sdhci_readl(host, SDHCI_PRESENT_STATE) & mask))
                                continue;
                        sdhci_writel(host, rdy, SDHCI_INT_STATUS);
                        sdhci_transfer_pio(host, data);
                        data->dest += data->blocksize;
-                       if (++block >= data->blocks)
-                               break;
+                       if (++block >= data->blocks) {
+                               /* Keep looping until the SDHCI_INT_DATA_END is
+                                * cleared, even if we finished sending all the
+                                * blocks.
+                                */
+                               transfer_done = true;
+                               continue;
+                       }
                }
 #ifdef CONFIG_MMC_SDHCI_SDMA
-               if (stat & SDHCI_INT_DMA_END) {
+               if (!transfer_done && (stat & SDHCI_INT_DMA_END)) {
                        sdhci_writel(host, SDHCI_INT_DMA_END, SDHCI_INT_STATUS);
                        start_addr &= ~(SDHCI_DEFAULT_BOUNDARY_SIZE - 1);
                        start_addr += SDHCI_DEFAULT_BOUNDARY_SIZE;