hw/sd/bcm2835_sdhost: Fix PIO mode writes

Writes in PIO mode have two requirements:

- A data interrupt must be generated after a write command has been
  issued to indicate that the chip is ready to receive data.
- A block interrupt must be generated after each block to indicate
  that the chip is ready to receive the next data block.

Rearrange the code to make this happen. Tested on raspi3 (in PIO mode)
and raspi2 (in DMA mode).

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Message-id: 1531779837-20557-1-git-send-email-linux@roeck-us.net
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

hw/sd/bcm2835_sdhost.c

@@ -179,9 +179,11 @@ static void bcm2835_sdhost_fifo_run(BCM2835SDHostState *s)
     uint32_t value = 0;
     int n;
     int is_read;
+    int is_write;
 
     is_read = (s->cmd & SDCMD_READ_CMD) != 0;
-    if (s->datacnt != 0 && (!is_read || sdbus_data_ready(&s->sdbus))) {
+    is_write = (s->cmd & SDCMD_WRITE_CMD) != 0;
+    if (s->datacnt != 0 && (is_write || sdbus_data_ready(&s->sdbus))) {
         if (is_read) {
             n = 0;
             while (s->datacnt && s->fifo_len < BCM2835_SDHOST_FIFO_LEN) {
@@ -201,8 +203,11 @@ static void bcm2835_sdhost_fifo_run(BCM2835SDHostState *s)
             if (n != 0) {
                 bcm2835_sdhost_fifo_push(s, value);
                 s->status |= SDHSTS_DATA_FLAG;
+                if (s->config & SDHCFG_DATA_IRPT_EN) {
+                    s->status |= SDHSTS_SDIO_IRPT;
+                }
             }
-        } else { /* write */
+        } else if (is_write) { /* write */
             n = 0;
             while (s->datacnt > 0 && (s->fifo_len > 0 || n > 0)) {
                 if (n == 0) {
@@ -223,11 +228,18 @@ static void bcm2835_sdhost_fifo_run(BCM2835SDHostState *s)
             s->edm &= ~SDEDM_FSM_MASK;
             s->edm |= SDEDM_FSM_DATAMODE;
             trace_bcm2835_sdhost_edm_change("datacnt 0", s->edm);
-
-            if ((s->cmd & SDCMD_WRITE_CMD) &&
+        }
+        if (is_write) {
+            /* set block interrupt at end of each block transfer */
+            if (s->hbct && s->datacnt % s->hbct == 0 &&
                 (s->config & SDHCFG_BLOCK_IRPT_EN)) {
                 s->status |= SDHSTS_BLOCK_IRPT;
             }
+            /* set data interrupt after each transfer */
+            s->status |= SDHSTS_DATA_FLAG;
+            if (s->config & SDHCFG_DATA_IRPT_EN) {
+                s->status |= SDHSTS_SDIO_IRPT;
+            }
         }
     }