[PATCH v3] isdn: hfc_{pci,sx}: Avoid empty body if statements

From: Nathan Chancellor
Date: Thu Oct 18 2018 - 21:12:18 EST


Clang warns:

drivers/isdn/hisax/hfc_pci.c:131:34: error: if statement has empty body
[-Werror,-Wempty-body]
if (Read_hfc(cs, HFCPCI_INT_S1));
^
drivers/isdn/hisax/hfc_pci.c:131:34: note: put the semicolon on a
separate line to silence this warning

In my attempt to hide the warnings because I thought they didn't serve
any purpose[1], Masahiro Yamada pointed out that {Read,Write}_hfc in
hci_pci.c should be using a standard register access method; otherwise,
the compiler will just remove the if statements.

For hfc_pci, use the versions of {Read,Write}_hfc found in
drivers/isdn/hardware/mISDN/hfc_pCI.h while converting pci_io to be
'void __iomem *' (and clean up ioremap) then remove the empty if
statements.

For hfc_sx, {Read,Write}_hfc are already use a proper register accessor
(inb, outb) so just remove the unnecessary if statements.

[1]: https://lore.kernel.org/lkml/20181016021454.11953-1-natechancellor@xxxxxxxxx/

Link: https://github.com/ClangBuiltLinux/linux/issues/66
Suggested-by: Masahiro Yamada <yamada.masahiro@xxxxxxxxxxxxx>
Signed-off-by: Nathan Chancellor <natechancellor@xxxxxxxxx>
---

v1 -> v2:

* Remove unnecessary cast to void, just remove if statements (thanks to
review from Masahiro).

* Clean up commit message.

v2 -> v3:

* Convert hfc_pci to properly use readb/writeb to avoid static checker
issues.

drivers/isdn/hisax/hfc_pci.c | 11 +++++------
drivers/isdn/hisax/hfc_pci.h | 4 ++--
drivers/isdn/hisax/hfc_sx.c | 6 +++---
drivers/isdn/hisax/hisax.h | 2 +-
4 files changed, 11 insertions(+), 12 deletions(-)

diff --git a/drivers/isdn/hisax/hfc_pci.c b/drivers/isdn/hisax/hfc_pci.c
index 8e5b03161b2f..ea0e4c6de3fb 100644
--- a/drivers/isdn/hisax/hfc_pci.c
+++ b/drivers/isdn/hisax/hfc_pci.c
@@ -86,7 +86,7 @@ release_io_hfcpci(struct IsdnCardState *cs)
pci_free_consistent(cs->hw.hfcpci.dev, 0x8000,
cs->hw.hfcpci.fifos, cs->hw.hfcpci.dma);
cs->hw.hfcpci.fifos = NULL;
- iounmap((void *)cs->hw.hfcpci.pci_io);
+ iounmap(cs->hw.hfcpci.pci_io);
}

/********************************************************************************/
@@ -128,7 +128,7 @@ reset_hfcpci(struct IsdnCardState *cs)
Write_hfc(cs, HFCPCI_INT_M1, cs->hw.hfcpci.int_m1);

/* Clear already pending ints */
- if (Read_hfc(cs, HFCPCI_INT_S1));
+ Read_hfc(cs, HFCPCI_INT_S1);

Write_hfc(cs, HFCPCI_STATES, HFCPCI_LOAD_STATE | 2); /* HFC ST 2 */
udelay(10);
@@ -158,7 +158,7 @@ reset_hfcpci(struct IsdnCardState *cs)
/* Finally enable IRQ output */
cs->hw.hfcpci.int_m2 = HFCPCI_IRQ_ENABLE;
Write_hfc(cs, HFCPCI_INT_M2, cs->hw.hfcpci.int_m2);
- if (Read_hfc(cs, HFCPCI_INT_S1));
+ Read_hfc(cs, HFCPCI_INT_S1);
}

/***************************************************/
@@ -1537,7 +1537,7 @@ hfcpci_bh(struct work_struct *work)
cs->hw.hfcpci.int_m1 &= ~HFCPCI_INTS_TIMER;
Write_hfc(cs, HFCPCI_INT_M1, cs->hw.hfcpci.int_m1);
/* Clear already pending ints */
- if (Read_hfc(cs, HFCPCI_INT_S1));
+ Read_hfc(cs, HFCPCI_INT_S1);
Write_hfc(cs, HFCPCI_STATES, 4 | HFCPCI_LOAD_STATE);
udelay(10);
Write_hfc(cs, HFCPCI_STATES, 4);
@@ -1692,7 +1692,7 @@ setup_hfcpci(struct IsdnCard *card)
printk(KERN_WARNING "HFC-PCI: No IRQ for PCI card found\n");
return (0);
}
- cs->hw.hfcpci.pci_io = (char *)(unsigned long)dev_hfcpci->resource[1].start;
+ cs->hw.hfcpci.pci_io = ioremap(dev_hfcpci->resource[1].start, 256);
printk(KERN_INFO "HiSax: HFC-PCI card manufacturer: %s card name: %s\n", id_list[i].vendor_name, id_list[i].card_name);

if (!cs->hw.hfcpci.pci_io) {
@@ -1716,7 +1716,6 @@ setup_hfcpci(struct IsdnCard *card)
return 0;
}
pci_write_config_dword(cs->hw.hfcpci.dev, 0x80, (u32)cs->hw.hfcpci.dma);
- cs->hw.hfcpci.pci_io = ioremap((ulong) cs->hw.hfcpci.pci_io, 256);
printk(KERN_INFO
"HFC-PCI: defined at mem %p fifo %p(%lx) IRQ %d HZ %d\n",
cs->hw.hfcpci.pci_io,
diff --git a/drivers/isdn/hisax/hfc_pci.h b/drivers/isdn/hisax/hfc_pci.h
index 4e58700a3e61..4c3b3ba35726 100644
--- a/drivers/isdn/hisax/hfc_pci.h
+++ b/drivers/isdn/hisax/hfc_pci.h
@@ -228,8 +228,8 @@ typedef union {
} fifo_area;


-#define Write_hfc(a, b, c) (*(((u_char *)a->hw.hfcpci.pci_io) + b) = c)
-#define Read_hfc(a, b) (*(((u_char *)a->hw.hfcpci.pci_io) + b))
+#define Write_hfc(a, b, c) (writeb(c, (a->hw.hfcpci.pci_io) + b))
+#define Read_hfc(a, b) (readb((a->hw.hfcpci.pci_io) + b))

extern void main_irq_hcpci(struct BCState *bcs);
extern void releasehfcpci(struct IsdnCardState *cs);
diff --git a/drivers/isdn/hisax/hfc_sx.c b/drivers/isdn/hisax/hfc_sx.c
index 4d3b4b2f2612..12af628d9b2c 100644
--- a/drivers/isdn/hisax/hfc_sx.c
+++ b/drivers/isdn/hisax/hfc_sx.c
@@ -381,7 +381,7 @@ reset_hfcsx(struct IsdnCardState *cs)
Write_hfc(cs, HFCSX_INT_M1, cs->hw.hfcsx.int_m1);

/* Clear already pending ints */
- if (Read_hfc(cs, HFCSX_INT_S1));
+ Read_hfc(cs, HFCSX_INT_S1);

Write_hfc(cs, HFCSX_STATES, HFCSX_LOAD_STATE | 2); /* HFC ST 2 */
udelay(10);
@@ -411,7 +411,7 @@ reset_hfcsx(struct IsdnCardState *cs)
/* Finally enable IRQ output */
cs->hw.hfcsx.int_m2 = HFCSX_IRQ_ENABLE;
Write_hfc(cs, HFCSX_INT_M2, cs->hw.hfcsx.int_m2);
- if (Read_hfc(cs, HFCSX_INT_S2));
+ Read_hfc(cs, HFCSX_INT_S2);
}

/***************************************************/
@@ -1288,7 +1288,7 @@ hfcsx_bh(struct work_struct *work)
cs->hw.hfcsx.int_m1 &= ~HFCSX_INTS_TIMER;
Write_hfc(cs, HFCSX_INT_M1, cs->hw.hfcsx.int_m1);
/* Clear already pending ints */
- if (Read_hfc(cs, HFCSX_INT_S1));
+ Read_hfc(cs, HFCSX_INT_S1);

Write_hfc(cs, HFCSX_STATES, 4 | HFCSX_LOAD_STATE);
udelay(10);
diff --git a/drivers/isdn/hisax/hisax.h b/drivers/isdn/hisax/hisax.h
index 338d0408b377..40080e06421c 100644
--- a/drivers/isdn/hisax/hisax.h
+++ b/drivers/isdn/hisax/hisax.h
@@ -703,7 +703,7 @@ struct hfcPCI_hw {
unsigned char nt_mode;
int nt_timer;
struct pci_dev *dev;
- unsigned char *pci_io; /* start of PCI IO memory */
+ void __iomem *pci_io; /* start of PCI IO memory */
dma_addr_t dma; /* dma handle for Fifos */
void *fifos; /* FIFO memory */
int last_bfifo_cnt[2]; /* marker saving last b-fifo frame count */
--
2.19.1