[ARM] 3531/1: i.MX/MX1 SD/MMC ensure, that clock are stopped before new command and cleanups
Patch from Pavel Pisa
There has been problems that for some paths that clock are not stopped
during new command programming and initiation. Result is issuing
of incorrect command to the card. Some other problems are cleaned too.
Noisy report of known ERRATUM #4 has been suppressed.
Signed-off-by: Pavel Pisa <pisa@cmp.felk.cvut.cz>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
diff --git a/drivers/mmc/imxmmc.c b/drivers/mmc/imxmmc.c
index 79358e22..a4eb1d0 100644
--- a/drivers/mmc/imxmmc.c
+++ b/drivers/mmc/imxmmc.c
@@ -218,8 +218,10 @@
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 @@
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 @@
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 @@
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 @@
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 @@
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 {