ALSA: lx6464es - fix device communication via command bus

commit 6175ddf06b optimized the mem*io
functions that have been used to send commands to the device. these
optimizations somehow corrupted the communication with the lx6464es,
that resulted the device to be unusable with kernels after 2.6.33.

this patch emulates the memcpy_*_io functions via a loop to avoid these
problems.

Signed-off-by: Tim Blechmann <tim@klingt.org>
LKML-Reference: <4ECB5257.4040600@ladisch.de>
Cc: <stable@kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

sound/pci/lx6464es/lx_core.c

@@ -81,8 +81,12 @@ unsigned long lx_dsp_reg_read(struct lx6464es *chip, int port)
 static void lx_dsp_reg_readbuf(struct lx6464es *chip, int port, u32 *data,
 			       u32 len)
 {
-	void __iomem *address = lx_dsp_register(chip, port);
-	memcpy_fromio(data, address, len*sizeof(u32));
+	u32 __iomem *address = lx_dsp_register(chip, port);
+	int i;
+
+	/* we cannot use memcpy_fromio */
+	for (i = 0; i != len; ++i)
+		data[i] = ioread32(address + i);
 }
 
 
@@ -95,8 +99,12 @@ void lx_dsp_reg_write(struct lx6464es *chip, int port, unsigned data)
 static void lx_dsp_reg_writebuf(struct lx6464es *chip, int port,
 				const u32 *data, u32 len)
 {
-	void __iomem *address = lx_dsp_register(chip, port);
-	memcpy_toio(address, data, len*sizeof(u32));
+	u32 __iomem *address = lx_dsp_register(chip, port);
+	int i;
+
+	/* we cannot use memcpy_to */
+	for (i = 0; i != len; ++i)
+		iowrite32(data[i], address + i);
 }