[PATCH][2.4.28-pre3] USB drivers gcc-3.4 fixes

[PATCH][2.4.28-pre3] USB drivers gcc-3.4 fixes

[Mikael Pettersson]

This patch fixes gcc-3.4 cast-as-lvalue warnings in the 2.4.28-pre3
kernel's USB drivers. The audio.c and uss720.c changes are backports
from the 2.6 kernel. The hpusbscsi.c and microtek.c changes are new,
since the 2.6 code is different.

/Mikael

--- linux-2.4.28-pre3/drivers/usb/audio.c.~1~	2004-08-08 10:56:31.000000000 +0200
+++ linux-2.4.28-pre3/drivers/usb/audio.c	2004-09-12 01:56:20.000000000 +0200
@@ -609,7 +609,7 @@
 			pgrem = rem;
 		memcpy((db->sgbuf[db->wrptr >> PAGE_SHIFT]) + (db->wrptr & (PAGE_SIZE-1)), buffer, pgrem);
 		size -= pgrem;
-		(char *)buffer += pgrem;
+		buffer += pgrem;
 		db->wrptr += pgrem;
 		if (db->wrptr >= db->dmasize)
 			db->wrptr = 0;
@@ -632,7 +632,7 @@
 			pgrem = rem;
 		memcpy(buffer, (db->sgbuf[db->rdptr >> PAGE_SHIFT]) + (db->rdptr & (PAGE_SIZE-1)), pgrem);
 		size -= pgrem;
-		(char *)buffer += pgrem;
+		buffer += pgrem;
 		db->rdptr += pgrem;
 		if (db->rdptr >= db->dmasize)
 			db->rdptr = 0;
@@ -657,7 +657,7 @@
 		if (copy_from_user((db->sgbuf[ptr >> PAGE_SHIFT]) + (ptr & (PAGE_SIZE-1)), buffer, pgrem))
 			return -EFAULT;
 		size -= pgrem;
-		(char *)buffer += pgrem;
+		buffer += pgrem;
 		ptr += pgrem;
 		if (ptr >= db->dmasize)
 			ptr = 0;
@@ -682,7 +682,7 @@
 		if (copy_to_user(buffer, (db->sgbuf[ptr >> PAGE_SHIFT]) + (ptr & (PAGE_SIZE-1)), pgrem))
 			return -EFAULT;
 		size -= pgrem;
-		(char *)buffer += pgrem;
+		buffer += pgrem;
 		ptr += pgrem;
 		if (ptr >= db->dmasize)
 			ptr = 0;
--- linux-2.4.28-pre3/drivers/usb/hpusbscsi.c.~1~	2003-06-14 13:30:26.000000000 +0200
+++ linux-2.4.28-pre3/drivers/usb/hpusbscsi.c	2004-09-12 01:56:20.000000000 +0200
@@ -182,7 +182,7 @@
 
 	memcpy (&(new->ctempl), &hpusbscsi_scsi_host_template,
 		sizeof (hpusbscsi_scsi_host_template));
-	(struct hpusbscsi *) new->ctempl.proc_dir = new;
+	new->ctempl.proc_dir = (void *) new;
 	new->ctempl.module = THIS_MODULE;
 
 	if (scsi_register_module (MODULE_SCSI_HA, &(new->ctempl)))
--- linux-2.4.28-pre3/drivers/usb/microtek.c.~1~	2002-11-30 17:12:27.000000000 +0100
+++ linux-2.4.28-pre3/drivers/usb/microtek.c	2004-09-12 01:56:20.000000000 +0200
@@ -987,7 +987,7 @@
 	/* Initialize the host template based on the default one */
 	memcpy(&(new_desc->ctempl), &mts_scsi_host_template, sizeof(mts_scsi_host_template));
 	/* HACK from usb-storage - this is needed for scsi detection */
-	(struct mts_desc *)new_desc->ctempl.proc_dir = new_desc; /* FIXME */
+	new_desc->ctempl.proc_dir = (void *)new_desc; /* FIXME */
 
 	MTS_DEBUG("registering SCSI module\n");
 
--- linux-2.4.28-pre3/drivers/usb/uss720.c.~1~	2001-10-24 11:59:14.000000000 +0200
+++ linux-2.4.28-pre3/drivers/usb/uss720.c	2004-09-12 01:56:20.000000000 +0200
@@ -333,7 +333,7 @@
 	for (; got < length; got++) {
 		if (get_1284_register(pp, 4, (char *)buf))
 			break;
-		((char*)buf)++;
+		buf++;
 		if (priv->reg[0] & 0x01) {
 			clear_epp_timeout(pp);
 			break;
@@ -392,7 +392,7 @@
 	for (; got < length; got++) {
 		if (get_1284_register(pp, 3, (char *)buf))
 			break;
-		((char*)buf)++;
+		buf++;
 		if (priv->reg[0] & 0x01) {
 			clear_epp_timeout(pp);
 			break;
@@ -412,7 +412,7 @@
 	for (; written < length; written++) {
 		if (set_1284_register(pp, 3, *(char *)buf))
 			break;
-		((char*)buf)++;
+		buf++;
 		if (get_1284_register(pp, 1, NULL))
 			break;
 		if (priv->reg[0] & 0x01) {
@@ -469,7 +469,7 @@
 	for (; written < len; written++) {
 		if (set_1284_register(pp, 5, *(char *)buffer))
 			break;
-		((char*)buffer)++;
+		buffer++;
 	}
 	change_mode(pp, ECR_PS2);
 	return written;

Re: [PATCH][2.4.28-pre3] USB drivers gcc-3.4 fixes

[Pete Zaitcev]

On Sun, 12 Sep 2004 13:29:05 +0200 (MEST)
Mikael Pettersson <mikpe@csd.uu.se> wrote:

> This patch fixes gcc-3.4 cast-as-lvalue warnings in the 2.4.28-pre3
> kernel's USB drivers. The audio.c and uss720.c changes are backports
> from the 2.6 kernel. The hpusbscsi.c and microtek.c changes are new,
> since the 2.6 code is different.

> +++ linux-2.4.28-pre3/drivers/usb/audio.c	2004-09-12 01:56:20.000000000 +0200
> @@ -609,7 +609,7 @@
>  		size -= pgrem;
> -		(char *)buffer += pgrem;
> +		buffer += pgrem;

I'm pretty sure it's done that way on purpose. There were compilers which
did not allow any arithmetics on void*, and it had to be cast to char*.
So perhaps it's correct for 2.6, which requires gcc 3 anyway, but I have
my doubts about applicability of this to 2.4.

-- Pete

Re: [PATCH][2.4.28-pre3] USB drivers gcc-3.4 fixes

[Pete Zaitcev]

How about this now?

-- Pete

diff -urp -X dontdiff linux-2.4.28-pre3/drivers/usb/audio.c linux-2.4.28-pre3-usb/drivers/usb/audio.c
--- linux-2.4.28-pre3/drivers/usb/audio.c	2004-08-24 12:38:50.000000000 -0700
+++ linux-2.4.28-pre3-usb/drivers/usb/audio.c	2004-09-12 17:49:35.000000000 -0700
@@ -593,9 +593,10 @@ static int dmabuf_mmap(struct dmabuf *db
 	return 0;
 }
 
-static void dmabuf_copyin(struct dmabuf *db, const void *buffer, unsigned int size)
+static void dmabuf_copyin(struct dmabuf *db, const void *_buffer, unsigned int size)
 {
 	unsigned int pgrem, rem;
+	const char *buffer = _buffer;
 
 	db->total_bytes += size;
 	for (;;) {
@@ -609,16 +610,17 @@ static void dmabuf_copyin(struct dmabuf 
 			pgrem = rem;
 		memcpy((db->sgbuf[db->wrptr >> PAGE_SHIFT]) + (db->wrptr & (PAGE_SIZE-1)), buffer, pgrem);
 		size -= pgrem;
-		(char *)buffer += pgrem;
+		buffer += pgrem;
 		db->wrptr += pgrem;
 		if (db->wrptr >= db->dmasize)
 			db->wrptr = 0;
 	}
 }
 
-static void dmabuf_copyout(struct dmabuf *db, void *buffer, unsigned int size)
+static void dmabuf_copyout(struct dmabuf *db, void *_buffer, unsigned int size)
 {
 	unsigned int pgrem, rem;
+	char *buffer = _buffer;
 
 	db->total_bytes += size;
 	for (;;) {
@@ -632,16 +634,17 @@ static void dmabuf_copyout(struct dmabuf
 			pgrem = rem;
 		memcpy(buffer, (db->sgbuf[db->rdptr >> PAGE_SHIFT]) + (db->rdptr & (PAGE_SIZE-1)), pgrem);
 		size -= pgrem;
-		(char *)buffer += pgrem;
+		buffer += pgrem;
 		db->rdptr += pgrem;
 		if (db->rdptr >= db->dmasize)
 			db->rdptr = 0;
 	}
 }
 
-static int dmabuf_copyin_user(struct dmabuf *db, unsigned int ptr, const void *buffer, unsigned int size)
+static int dmabuf_copyin_user(struct dmabuf *db, unsigned int ptr, const void *_buffer, unsigned int size)
 {
 	unsigned int pgrem, rem;
+	const char *buffer = _buffer;
 
 	if (!db->ready || db->mapped)
 		return -EINVAL;
@@ -657,16 +660,17 @@ static int dmabuf_copyin_user(struct dma
 		if (copy_from_user((db->sgbuf[ptr >> PAGE_SHIFT]) + (ptr & (PAGE_SIZE-1)), buffer, pgrem))
 			return -EFAULT;
 		size -= pgrem;
-		(char *)buffer += pgrem;
+		buffer += pgrem;
 		ptr += pgrem;
 		if (ptr >= db->dmasize)
 			ptr = 0;
 	}
 }
 
-static int dmabuf_copyout_user(struct dmabuf *db, unsigned int ptr, void *buffer, unsigned int size)
+static int dmabuf_copyout_user(struct dmabuf *db, unsigned int ptr, void *_buffer, unsigned int size)
 {
 	unsigned int pgrem, rem;
+	char *buffer = _buffer;
 
 	if (!db->ready || db->mapped)
 		return -EINVAL;
@@ -682,7 +686,7 @@ static int dmabuf_copyout_user(struct dm
 		if (copy_to_user(buffer, (db->sgbuf[ptr >> PAGE_SHIFT]) + (ptr & (PAGE_SIZE-1)), pgrem))
 			return -EFAULT;
 		size -= pgrem;
-		(char *)buffer += pgrem;
+		buffer += pgrem;
 		ptr += pgrem;
 		if (ptr >= db->dmasize)
 			ptr = 0;
diff -urp -X dontdiff linux-2.4.28-pre3/drivers/usb/hpusbscsi.c linux-2.4.28-pre3-usb/drivers/usb/hpusbscsi.c
--- linux-2.4.28-pre3/drivers/usb/hpusbscsi.c	2003-06-13 07:51:36.000000000 -0700
+++ linux-2.4.28-pre3-usb/drivers/usb/hpusbscsi.c	2004-09-12 17:23:57.000000000 -0700
@@ -182,7 +182,7 @@ hpusbscsi_usb_probe (struct usb_device *
 
 	memcpy (&(new->ctempl), &hpusbscsi_scsi_host_template,
 		sizeof (hpusbscsi_scsi_host_template));
-	(struct hpusbscsi *) new->ctempl.proc_dir = new;
+	new->ctempl.proc_dir = (void *) new;
 	new->ctempl.module = THIS_MODULE;
 
 	if (scsi_register_module (MODULE_SCSI_HA, &(new->ctempl)))
diff -urp -X dontdiff linux-2.4.28-pre3/drivers/usb/microtek.c linux-2.4.28-pre3-usb/drivers/usb/microtek.c
--- linux-2.4.28-pre3/drivers/usb/microtek.c	2002-11-28 15:53:14.000000000 -0800
+++ linux-2.4.28-pre3-usb/drivers/usb/microtek.c	2004-09-12 17:23:58.000000000 -0700
@@ -987,7 +987,7 @@ static void * mts_usb_probe (struct usb_
 	/* Initialize the host template based on the default one */
 	memcpy(&(new_desc->ctempl), &mts_scsi_host_template, sizeof(mts_scsi_host_template));
 	/* HACK from usb-storage - this is needed for scsi detection */
-	(struct mts_desc *)new_desc->ctempl.proc_dir = new_desc; /* FIXME */
+	new_desc->ctempl.proc_dir = (void *)new_desc; /* FIXME */
 
 	MTS_DEBUG("registering SCSI module\n");
 
diff -urp -X dontdiff linux-2.4.28-pre3/drivers/usb/uss720.c linux-2.4.28-pre3-usb/drivers/usb/uss720.c
--- linux-2.4.28-pre3/drivers/usb/uss720.c	2001-10-20 19:13:11.000000000 -0700
+++ linux-2.4.28-pre3-usb/drivers/usb/uss720.c	2004-09-12 20:48:13.000000000 -0700
@@ -327,13 +327,14 @@ static size_t parport_uss720_epp_read_da
 {
 	struct parport_uss720_private *priv = pp->private_data;	
 	size_t got = 0;
+	char *buff = buf;
 
 	if (change_mode(pp, ECR_EPP))
 		return 0;
 	for (; got < length; got++) {
-		if (get_1284_register(pp, 4, (char *)buf))
+		if (get_1284_register(pp, 4, buff))
 			break;
-		((char*)buf)++;
+		buff++;
 		if (priv->reg[0] & 0x01) {
 			clear_epp_timeout(pp);
 			break;
@@ -348,13 +349,14 @@ static size_t parport_uss720_epp_write_d
 #if 0
 	struct parport_uss720_private *priv = pp->private_data;	
 	size_t written = 0;
+	const char *buff = buf;
 
 	if (change_mode(pp, ECR_EPP))
 		return 0;
 	for (; written < length; written++) {
-		if (set_1284_register(pp, 4, (char *)buf))
+		if (set_1284_register(pp, 4, *buff))
 			break;
-		((char*)buf)++;
+		buff++;
 		if (get_1284_register(pp, 1, NULL))
 			break;
 		if (priv->reg[0] & 0x01) {
@@ -386,13 +388,14 @@ static size_t parport_uss720_epp_read_ad
 {
 	struct parport_uss720_private *priv = pp->private_data;	
 	size_t got = 0;
+	char *buff = buf;
 
 	if (change_mode(pp, ECR_EPP))
 		return 0;
 	for (; got < length; got++) {
-		if (get_1284_register(pp, 3, (char *)buf))
+		if (get_1284_register(pp, 3, buff))
 			break;
-		((char*)buf)++;
+		buff++;
 		if (priv->reg[0] & 0x01) {
 			clear_epp_timeout(pp);
 			break;
@@ -406,13 +409,14 @@ static size_t parport_uss720_epp_write_a
 {
 	struct parport_uss720_private *priv = pp->private_data;	
 	size_t written = 0;
+	const char *buff = buf;
 
 	if (change_mode(pp, ECR_EPP))
 		return 0;
 	for (; written < length; written++) {
-		if (set_1284_register(pp, 3, *(char *)buf))
+		if (set_1284_register(pp, 3, *buff))
 			break;
-		((char*)buf)++;
+		buff++;
 		if (get_1284_register(pp, 1, NULL))
 			break;
 		if (priv->reg[0] & 0x01) {
@@ -463,13 +467,14 @@ static size_t parport_uss720_ecp_read_da
 static size_t parport_uss720_ecp_write_addr(struct parport *pp, const void *buffer, size_t len, int flags)
 {
 	size_t written = 0;
+	const char *buff = buffer;
 
 	if (change_mode(pp, ECR_ECP))
 		return 0;
 	for (; written < len; written++) {
-		if (set_1284_register(pp, 5, *(char *)buffer))
+		if (set_1284_register(pp, 5, *buff))
 			break;
-		((char*)buffer)++;
+		buff++;
 	}
 	change_mode(pp, ECR_PS2);
 	return written;

Re: [PATCH][2.4.28-pre3] USB drivers gcc-3.4 fixes

[Alan Cox]

On Llu, 2004-09-13 at 01:30, Pete Zaitcev wrote:
> >  		size -= pgrem;
> > -		(char *)buffer += pgrem;
> > +		buffer += pgrem;
> 
> I'm pretty sure it's done that way on purpose. There were compilers which
> did not allow any arithmetics on void*, and it had to be cast to char*.
> So perhaps it's correct for 2.6, which requires gcc 3 anyway, but I have
> my doubts about applicability of this to 2.4.

Should be ok for the 2.* gcc we support. (BTW is anyone using anything
less than 2.95 nowdays because we've still got 2.7.* workarounds in
asm-i386/semaphore.h !)

Otherwise in "valid" C it's

	buffer = ((char *)buffer) + pgrem;

Re: [PATCH][2.4.28-pre3] USB drivers gcc-3.4 fixes

[Mikael Pettersson]

Pete Zaitcev writes:
 > How about this now?
 > 
 > -- Pete
 > 
 > diff -urp -X dontdiff linux-2.4.28-pre3/drivers/usb/audio.c linux-2.4.28-pre3-usb/drivers/usb/audio.c
 > --- linux-2.4.28-pre3/drivers/usb/audio.c	2004-08-24 12:38:50.000000000 -0700
 > +++ linux-2.4.28-pre3-usb/drivers/usb/audio.c	2004-09-12 17:49:35.000000000 -0700
 > @@ -593,9 +593,10 @@ static int dmabuf_mmap(struct dmabuf *db
 >  	return 0;
 >  }
 >  
 > -static void dmabuf_copyin(struct dmabuf *db, const void *buffer, unsigned int size)
 > +static void dmabuf_copyin(struct dmabuf *db, const void *_buffer, unsigned int size)
 >  {
 >  	unsigned int pgrem, rem;
 > +	const char *buffer = _buffer;

and more on the same theme.

Yeah, that's much nicer. Thanks.

Marcelo, please consider this patch instead of the one I sent.

/Mikael