* [PATCH] i2c-tiny-usb: Fix on big-endian systems
[not found] ` <20100122194807.1e2131d4-ig7AzVSIIG7kN2dkZ6Wm7A@public.gmane.org>
@ 2010-01-28 8:34 ` Jean Delvare
0 siblings, 0 replies; 2+ messages in thread
From: Jean Delvare @ 2010-01-28 8:34 UTC (permalink / raw)
To: Linux I2C; +Cc: Till Harbaum
The functionality bit vector is always returned as a little-endian
32-bit number by the device, so it must be byte-swapped to the host
endianness.
On the other hand, the delay value is handled by the USB stack, so no
byte swapping is needed on our side.
This fixes bug #15105:
http://bugzilla.kernel.org/show_bug.cgi?id=15105
Reported-by: Jens Richter <jens-dOUPgdA+p/6o8zYe/P2rPqhivhuVJJ3m@public.gmane.org>
Signed-off-by: Jean Delvare <khali-PUYAD+kWke1g9hUCZPvPmw@public.gmane.org>
Tested-by: Jens Richter <jens-dOUPgdA+p/6o8zYe/P2rPqhivhuVJJ3m@public.gmane.org>
Cc: Till Harbaum <till-RcHadlBFbzVAfugRpC6u6w@public.gmane.org>
Cc: stable-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org
---
drivers/i2c/busses/i2c-tiny-usb.c | 12 ++++++------
1 file changed, 6 insertions(+), 6 deletions(-)
--- linux-2.6.33-rc5.orig/drivers/i2c/busses/i2c-tiny-usb.c 2010-01-28 08:08:54.000000000 +0100
+++ linux-2.6.33-rc5/drivers/i2c/busses/i2c-tiny-usb.c 2010-01-28 09:13:30.000000000 +0100
@@ -13,6 +13,7 @@
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/module.h>
+#include <linux/types.h>
/* include interfaces to usb layer */
#include <linux/usb.h>
@@ -31,8 +32,8 @@
#define CMD_I2C_IO_END (1<<1)
/* i2c bit delay, default is 10us -> 100kHz */
-static int delay = 10;
-module_param(delay, int, 0);
+static unsigned short delay = 10;
+module_param(delay, ushort, 0);
MODULE_PARM_DESC(delay, "bit delay in microseconds, "
"e.g. 10 for 100kHz (default is 100kHz)");
@@ -109,7 +110,7 @@ static int usb_xfer(struct i2c_adapter *
static u32 usb_func(struct i2c_adapter *adapter)
{
- u32 func;
+ __le32 func;
/* get functionality from adapter */
if (usb_read(adapter, CMD_GET_FUNC, 0, 0, &func, sizeof(func)) !=
@@ -118,7 +119,7 @@ static u32 usb_func(struct i2c_adapter *
return 0;
}
- return func;
+ return le32_to_cpu(func);
}
/* This is the actual algorithm we define */
@@ -216,8 +217,7 @@ static int i2c_tiny_usb_probe(struct usb
"i2c-tiny-usb at bus %03d device %03d",
dev->usb_dev->bus->busnum, dev->usb_dev->devnum);
- if (usb_write(&dev->adapter, CMD_SET_DELAY,
- cpu_to_le16(delay), 0, NULL, 0) != 0) {
+ if (usb_write(&dev->adapter, CMD_SET_DELAY, delay, 0, NULL, 0) != 0) {
dev_err(&dev->adapter.dev,
"failure setting delay to %dus\n", delay);
retval = -EIO;
--
Jean Delvare
^ permalink raw reply [flat|nested] 2+ messages in thread