FROMLIST: mmc: dw_mmc: Fix the DTO timeout overflow calculation for 32-bit systems

In commit 9d9491a ("mmc: dw_mmc: Fix the DTO timeout calculation")
have been made
changes which cause multiply overflow for 32-bit systems.
The broken timeout calculations caused false interrupt latency warnings
and stacktrace splat (such as below) when accessing the SD Card.

| Running :  4M-check-reassembly-tcp-cmykw2-rotatew2.out -v0 -w1
| -  Info: Finished target initialization.
| mmcblk0: error -110 transferring data, sector 320544, nr 2048, cmd
response
|  0x900, card status 0x0
| mmc_host mmc0: Bus speed (slot 0) = 50000000Hz (slot req 400000Hz,
actual
| 396825HZ div = 63)
| mmc_host mmc0: Bus speed (slot 0) = 50000000Hz (slot req 25000000Hz,
actual
|  25000000HZ div = 1)
| ------------[ cut here ]------------
| softirq: huh, entered softirq 6 TASKLET 6f6a9412 with preempt_count
00000101,
| exited with 00000100?
| WARNING: CPU: 2 PID: 0 at ../lib/scatterlist.c:652
sg_miter_next+0x28/0x20c
| Modules linked in:
| CPU: 2 PID: 0 Comm: swapper/2 Not tainted 4.15.0 hardkernel#57
|
| Stack Trace:
|  arc_unwind_core.constprop.1+0xd0/0xf4
|  dump_stack+0x68/0x80
|  warn_slowpath_null+0x4e/0xec
|  sg_miter_next+0x28/0x20c
|  dw_mci_read_data_pio+0x44/0x190
|  dw_mmc f000a000.mmc: Unexpected interrupt latency
|   dw_mci_interrupt+0x3ee/0x530
|  __handle_irq_event_percpu+0x56/0x150
|  handle_irq_event+0x34/0x78
|  handle_level_irq+0x8e/0x120
|  generic_handle_irq+0x1c/0x2c
|  idu_cascade_isr+0x30/0x6c
|  __handle_domain_irq+0x72/0xc8
|  ret_from_exception+0x0/0x8
|---[ end trace 2a58c9af6c25fe51 ]---

Lets cast this multiply to u64 type which prevents overflow.

Tested-by: Vineet Gupta <[email protected]>
Fixes: 9d9491a ("mmc: dw_mmc: Fix the DTO timeout calculation")
Reported-by: Vineet Gupta <[email protected]> # ARC STAR
9001306872 HSDK, sdio: board crashes when copying big files
Signed-off-by: Evgeniy Didin <[email protected]>
CC: Alexey Brodkin <[email protected]>
CC: Eugeniy Paltsev <[email protected]>
CC: Douglas Anderson <[email protected]>
CC: Ulf Hansson <[email protected]>
CC: [email protected]
CC: [email protected]
Cc: <[email protected]>
Reviewed-by: Shawn Lin <[email protected]>
Change-Id: Ib7614b17116e53debe738787fc26a04beba5f388
Signed-off-by: Shawn Lin <[email protected]>

Author: EvgeniiDidin

drivers/mmc/host/dw_mmc.c

@@ -1768,8 +1768,8 @@ static void dw_mci_set_drto(struct dw_mci *host)
 	drto_div = (mci_readl(host, CLKDIV) & 0xff) * 2;
 	if (drto_div == 0)
 		drto_div = 1;
-	drto_ms = DIV_ROUND_UP(MSEC_PER_SEC * drto_clks * drto_div,
-			       host->bus_hz);
+	drto_ms = DIV_ROUND_UP_ULL(MSEC_PER_SEC * drto_clks * drto_div,
+				   host->bus_hz);
 
 	/* add a bit spare time */
 	drto_ms += 10;