Commit d52786dd authored by Daniel Scheller's avatar Daniel Scheller Committed by Mauro Carvalho Chehab
Browse files

media: ddbridge: make (ddb)readl in while-loops fail-safe 



Reported by smatch:

  drivers/media/pci/ddbridge/ddbridge-core.c:1246 input_tasklet() warn: this loop depends on readl() succeeding
  drivers/media/pci/ddbridge/ddbridge-core.c:1768 flashio() warn: this loop depends on readl() succeeding
  drivers/media/pci/ddbridge/ddbridge-core.c:1788 flashio() warn: this loop depends on readl() succeeding

Fix this by introducing safe_ddbreadl() which will wrap ddbreadl and checks
for all bits set in the return which indicates failure, and return 0 in
that case. Usable as drop-in-replacement in all affected while loops w/o
having to change the logic.

Signed-off-by: default avatarDaniel Scheller <d.scheller@gmx.net>
Signed-off-by: default avatarMauro Carvalho Chehab <mchehab@s-opensource.com>
parent cb778f5c

drivers/media/pci/ddbridge/ddbridge-core.c

+18 −5
Original line number Diff line number Diff line
@@ -114,6 +114,19 @@ static int i2c_write_reg(struct i2c_adapter *adap, u8 adr, 
	return i2c_write(adap, adr, msg, 2);

}



static inline u32 safe_ddbreadl(struct ddb *dev, u32 adr)

{

	u32 val = ddbreadl(adr);



	/* (ddb)readl returns (uint)-1 (all bits set) on failure, catch that */

	if (val == ~0) {

		printk(KERN_ERR "ddbreadl failure, adr=%08x\n", adr);

		return 0;

	}



	return val;

}



static int ddb_i2c_cmd(struct ddb_i2c *i2c, u32 adr, u32 cmd)

{

	struct ddb *dev = i2c->dev;
@@ -1243,7 +1256,7 @@ static void input_tasklet(unsigned long data) 
		if (4&ddbreadl(DMA_BUFFER_CONTROL(input->nr)))

			printk(KERN_ERR "Overflow input %d\n", input->nr);

		while (input->cbuf != ((input->stat >> 11) & 0x1f)

		       || (4&ddbreadl(DMA_BUFFER_CONTROL(input->nr)))) {

		       || (4 & safe_ddbreadl(dev, DMA_BUFFER_CONTROL(input->nr)))) {

			dvb_dmx_swfilter_packets(&input->demux,

						 input->vbuf[input->cbuf],

						 input->dma_buf_size / 188);
@@ -1765,7 +1778,7 @@ static int flashio(struct ddb *dev, u8 *wbuf, u32 wlen, u8 *rbuf, u32 rlen) 
		wbuf += 4;

		wlen -= 4;

		ddbwritel(data, SPI_DATA);

		while (ddbreadl(SPI_CONTROL) & 0x0004)

		while (safe_ddbreadl(dev, SPI_CONTROL) & 0x0004)

			;

	}
@@ -1785,7 +1798,7 @@ static int flashio(struct ddb *dev, u8 *wbuf, u32 wlen, u8 *rbuf, u32 rlen) 
	if (shift)

		data <<= shift;

	ddbwritel(data, SPI_DATA);

	while (ddbreadl(SPI_CONTROL) & 0x0004)

	while (safe_ddbreadl(dev, SPI_CONTROL) & 0x0004)

		;



	if (!rlen) {
@@ -1797,7 +1810,7 @@ static int flashio(struct ddb *dev, u8 *wbuf, u32 wlen, u8 *rbuf, u32 rlen) 


	while (rlen > 4) {

		ddbwritel(0xffffffff, SPI_DATA);

		while (ddbreadl(SPI_CONTROL) & 0x0004)

		while (safe_ddbreadl(dev, SPI_CONTROL) & 0x0004)

			;

		data = ddbreadl(SPI_DATA);

		*(u32 *) rbuf = swab32(data);
@@ -1806,7 +1819,7 @@ static int flashio(struct ddb *dev, u8 *wbuf, u32 wlen, u8 *rbuf, u32 rlen) 
	}

	ddbwritel(0x0003 | ((rlen << (8 + 3)) & 0x1F00), SPI_CONTROL);

	ddbwritel(0xffffffff, SPI_DATA);

	while (ddbreadl(SPI_CONTROL) & 0x0004)

	while (safe_ddbreadl(dev, SPI_CONTROL) & 0x0004)

		;



	data = ddbreadl(SPI_DATA);