[ARM] 3531/1: i.MX/MX1 SD/MMC ensure, that clock are stopped before new command and...

[lisovros/linux_canprio.git] / drivers / mmc / imxmmc.c

diff --git a/drivers/mmc/imxmmc.c b/drivers/mmc/imxmmc.c
index 79358e223f5788fdd8dac33c24ce11170ec2ca5c..a4eb1d0e7a7169e381847c978c71b7bcb4dd72f1 100644 (file)
--- a/drivers/mmc/imxmmc.c
+++ b/drivers/mmc/imxmmc.c
@@ -218,8 +218,10 @@ static int imxmci_busy_wait_for_status(struct imxmci_host *host,
        if(!loops)
                return 0;
 
-       dev_info(mmc_dev(host->mmc), "busy wait for %d usec in %s, STATUS = 0x%x (0x%x)\n",
-               loops, where, *pstat, stat_mask);
+       /* The busy-wait is expected there for clock <8MHz due to SDHC hardware flaws */
+       if(!(stat_mask & STATUS_END_CMD_RESP) || (host->mmc->ios.clock>=8000000))
+               dev_info(mmc_dev(host->mmc), "busy wait for %d usec in %s, STATUS = 0x%x (0x%x)\n",
+                       loops, where, *pstat, stat_mask);
        return loops;
 }
 
@@ -333,6 +335,9 @@ static void imxmci_start_cmd(struct imxmci_host *host, struct mmc_command *cmd,
        WARN_ON(host->cmd != NULL);
        host->cmd = cmd;
 
+       /* Ensure, that clock are stopped else command programming and start fails */
+       imxmci_stop_clock(host);
+
        if (cmd->flags & MMC_RSP_BUSY)
                cmdat |= CMD_DAT_CONT_BUSY;
 
@@ -553,7 +558,7 @@ static int imxmci_cpu_driven_data(struct imxmci_host *host, unsigned int *pstat)
        int trans_done = 0;
        unsigned int stat = *pstat;
 
-       if(host->actual_bus_width == MMC_BUS_WIDTH_4)
+       if(host->actual_bus_width != MMC_BUS_WIDTH_4)
                burst_len = 16;
        else
                burst_len = 64;
@@ -591,8 +596,7 @@ static int imxmci_cpu_driven_data(struct imxmci_host *host, unsigned int *pstat)
                        stat = MMC_STATUS;
 
                        /* Flush extra bytes from FIFO */
-                       while(flush_len >= 2){
-                               flush_len -= 2;
+                       while(flush_len && !(stat & STATUS_DATA_TRANS_DONE)){
                                i = MMC_BUFFER_ACCESS;
                                stat = MMC_STATUS;
                                stat &= ~STATUS_CRC_READ_ERR; /* Stupid but required there */
@@ -746,10 +750,6 @@ static void imxmci_tasklet_fnc(unsigned long data)
                        data_dir_mask = STATUS_DATA_TRANS_DONE;
                }
 
-               imxmci_busy_wait_for_status(host, &stat,
-                               data_dir_mask,
-                               50, "imxmci_tasklet_fnc data");
-
                if(stat & data_dir_mask) {
                        clear_bit(IMXMCI_PEND_DMA_END_b, &host->pending_events);
                        imxmci_data_done(host, stat);
@@ -865,7 +865,11 @@ static void imxmci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
 
                imxmci_stop_clock(host);
                MMC_CLK_RATE = (prescaler<<3) | clk;
-               imxmci_start_clock(host);
+               /*
+                * Under my understanding, clock should not be started there, because it would
+                * initiate SDHC sequencer and send last or random command into card
+                */
+               /*imxmci_start_clock(host);*/
 
                dev_dbg(mmc_dev(host->mmc), "MMC_CLK_RATE: 0x%08x\n", MMC_CLK_RATE);
        } else {