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authorJon Medhurst <jon.medhurst@linaro.org>2011-10-04 13:10:10 +0100
committerJohn Rigby <john.rigby@linaro.org>2011-10-12 10:04:34 -0600
commit267bd462e5d4e1f4f7b4d50d8676a5d48928ef27 (patch)
treeff5dcfcd1d161e3a0bc07c3a4bb0c3628e2ba665
parent307335dd31d5160b0ec9d87ae51c77ba061f29af (diff)
MMC: PL180: Fix infinite loop with VExpress extended fifo implementation
The new IO FPGA implementation for Versatile Express contains an MMCI (PL180) cell with the FIFO extended to 128 words. This causes the read_bytes() function to go into an infinite loop; as it will wait for for the half-full signal (SDI_STA_RXFIFOBR) if there are more than 8 words remaining (SDI_FIFO_BURST_SIZE), but it won't receive this signal once there are fewer than 64 words left to transfer. One possible fix is to add some build time configuration to change SDI_FIFO_BURST_SIZE for the new implementation. However, the problematic code only seems to exist as a small performance optimisation, so the solution implemented by this patch is to simply remove it. The error checking following the loop is also removed as this will be handled by code further down the function. Cc: Andy Fleming <afleming@gmail.com> Signed-off-by: Jon Medhurst <jon.medhurst@linaro.org>
-rw-r--r--drivers/mmc/arm_pl180_mmci.c26
1 files changed, 0 insertions, 26 deletions
diff --git a/drivers/mmc/arm_pl180_mmci.c b/drivers/mmc/arm_pl180_mmci.c
index ed296ee02..e6467a2d1 100644
--- a/drivers/mmc/arm_pl180_mmci.c
+++ b/drivers/mmc/arm_pl180_mmci.c
@@ -111,7 +111,6 @@ static int do_command(struct mmc *dev, struct mmc_cmd *cmd)
static int read_bytes(struct mmc *dev, u32 *dest, u32 blkcount, u32 blksize)
{
u32 *tempbuff = dest;
- int i;
u64 xfercount = blkcount * blksize;
struct mmc_host *host = dev->priv;
u32 status, status_err;
@@ -121,31 +120,6 @@ static int read_bytes(struct mmc *dev, u32 *dest, u32 blkcount, u32 blksize)
status = readl(&host->base->status);
status_err = status & (SDI_STA_DCRCFAIL | SDI_STA_DTIMEOUT |
SDI_STA_RXOVERR);
- while (!status_err &&
- (xfercount >= SDI_FIFO_BURST_SIZE * sizeof(u32))) {
- if (status & SDI_STA_RXFIFOBR) {
- for (i = 0; i < SDI_FIFO_BURST_SIZE; i++)
- *(tempbuff + i) = readl(&host->base->fifo);
- tempbuff += SDI_FIFO_BURST_SIZE;
- xfercount -= SDI_FIFO_BURST_SIZE * sizeof(u32);
- }
- status = readl(&host->base->status);
- status_err = status &
- (SDI_STA_DCRCFAIL | SDI_STA_DTIMEOUT | SDI_STA_RXOVERR);
- }
-
- if (status & SDI_STA_DTIMEOUT) {
- printf("Read data timed out, xfercount: %llu, status: 0x%08X\n",
- xfercount, status);
- return -ETIMEDOUT;
- } else if (status & SDI_STA_DCRCFAIL) {
- printf("Read data blk CRC error: 0x%x\n", status);
- return -EILSEQ;
- } else if (status & SDI_STA_RXOVERR) {
- printf("Read data RX overflow error\n");
- return -EIO;
- }
-
while ((!status_err) && (xfercount >= sizeof(u32))) {
if (status & SDI_STA_RXDAVL) {
*(tempbuff) = readl(&host->base->fifo);