@@ -363,6 +363,7 @@ struct pl022 {
void *rx_end;
enum ssp_reading read;
enum ssp_writing write;
+ u32 exp_fifo_level;
};
/**
@@ -501,6 +502,9 @@ static int flush(struct pl022 *pl022)
while (readw(SSP_SR(pl022->virtbase)) & SSP_SR_MASK_RNE)
readw(SSP_DR(pl022->virtbase));
} while ((readw(SSP_SR(pl022->virtbase)) & SSP_SR_MASK_BSY) && limit--);
+
+ pl022->exp_fifo_level = 0;
+
return limit;
}
@@ -583,10 +587,9 @@ static void readwriter(struct pl022 *pl022)
* errons in 8bit wide transfers on ARM variants (just 8 words
* FIFO, means only 8x8 = 64 bits in FIFO) at least.
*
- * FIXME: currently we have no logic to account for this.
- * perhaps there is even something broken in HW regarding
- * 8bit transfers (it doesn't fail on 16bit) so this needs
- * more investigation...
+ * To prevent this issue, the TX FIFO is only filled to the
+ * unused RX FIFO fill length, regardless of what the TX
+ * FIFO status flag indicates.
*/
dev_dbg(&pl022->adev->dev,
"%s, rx: %p, rxend: %p, tx: %p, txend: %p\n",
@@ -613,11 +616,12 @@ static void readwriter(struct pl022 *pl022)
break;
}
pl022->rx += (pl022->cur_chip->n_bytes);
+ pl022->exp_fifo_level--;
}
/*
- * Write as much as you can, while keeping an eye on the RX FIFO!
+ * Write as much as possible up to the RX FIFO size
*/
- while ((readw(SSP_SR(pl022->virtbase)) & SSP_SR_MASK_TNF)
+ while ((pl022->exp_fifo_level < pl022->vendor->fifodepth)
&& (pl022->tx < pl022->tx_end)) {
switch (pl022->write) {
case WRITING_NULL:
@@ -634,6 +638,7 @@ static void readwriter(struct pl022 *pl022)
break;
}
pl022->tx += (pl022->cur_chip->n_bytes);
+ pl022->exp_fifo_level++;
/*
* This inner reader takes care of things appearing in the RX
* FIFO as we're transmitting. This will happen a lot since the
@@ -660,6 +665,7 @@ static void readwriter(struct pl022 *pl022)
break;
}
pl022->rx += (pl022->cur_chip->n_bytes);
+ pl022->exp_fifo_level--;
}
}
/*