From: Thomas Monjalon <thomas.monjalon@6wind.com>
To: dev@dpdk.org
Subject: [dpdk-dev] [PATCH 06/22] app: fix volatile read for GCC >= 4.6
Date: Wed, 20 Mar 2013 17:04:54 +0100 [thread overview]
Message-ID: <3e7f7fc9c0d5e01efa26eee1c1f4a23b8398890d.1363795499.git.thomas.monjalon@6wind.com> (raw)
In-Reply-To: <cover.1363795499.git.thomas.monjalon@6wind.com>
In-Reply-To: <cover.1363795499.git.thomas.monjalon@6wind.com>
From: Ivan Boule <ivan.boule@6wind.com>
When a memory address must be read, for instance a [mapped] PCI register,
the read value is assigned to a local variable that is not used after,
as for instance:
x = *((uint8_t *) mem_addr);
Such instructions do not compile with gcc 4.6.
The fix consists in adding the "volatile" attribute to the accessed data type
and to not assign the read value:
*((volatile uint8_t *) mem_addr);
Acked-by: Olivier Matz <olivier.matz@6wind.com>
Signed-off-by: Ivan Boule <ivan.boule@6wind.com>
---
app/test/test_memory.c | 4 +---
1 files changed, 1 insertions(+), 3 deletions(-)
diff --git a/app/test/test_memory.c b/app/test/test_memory.c
index 8a25eca..96d35d9 100644
--- a/app/test/test_memory.c
+++ b/app/test/test_memory.c
@@ -61,7 +61,6 @@ test_memory(void)
uint64_t s;
unsigned i, j;
const struct rte_memseg *mem;
- volatile uint8_t x;
/*
* dump the mapped memory: the python-expect script checks
@@ -83,8 +82,7 @@ test_memory(void)
/* check memory */
for (j = 0; j<mem[i].len; j++) {
- x = *((uint8_t *) mem[i].addr + j);
- RTE_SET_USED(x);
+ *((volatile uint8_t *) mem[i].addr + j);
}
}
--
1.7.2.5
next prev parent reply other threads:[~2013-03-20 16:07 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-03-20 16:04 [dpdk-dev] [PATCH 00/22] upgrade with 6WIND's enhancements Thomas Monjalon
2013-03-20 16:04 ` [dpdk-dev] [PATCH 01/22] mk: use $CC to detect toolchain version Thomas Monjalon
2013-03-20 16:04 ` [dpdk-dev] [PATCH 02/22] mk: fix typo in LDFLAGS for 32-bit Thomas Monjalon
2013-03-20 16:04 ` [dpdk-dev] [PATCH 03/22] mk: fix verbose display of install command Thomas Monjalon
2013-03-20 16:04 ` [dpdk-dev] [PATCH 04/22] mk: add a makefile for shared libraries Thomas Monjalon
2013-03-20 16:04 ` [dpdk-dev] [PATCH 05/22] mk: allow corei7-avx flag with gcc 4.7 Thomas Monjalon
2013-03-20 16:04 ` Thomas Monjalon [this message]
2013-03-20 16:04 ` [dpdk-dev] [PATCH 07/22] app: fix unused values Thomas Monjalon
2013-03-20 16:04 ` [dpdk-dev] [PATCH 08/22] app: use (void)variable when unused Thomas Monjalon
2013-03-20 16:04 ` [dpdk-dev] [PATCH 09/22] app: fix testpmd compliance with __rte_mbuf_sanity_check() Thomas Monjalon
2013-03-20 16:04 ` [dpdk-dev] [PATCH 10/22] app: fix config crash in testpmd Thomas Monjalon
2013-03-20 16:04 ` [dpdk-dev] [PATCH 11/22] app: fix autotest summary in error cases Thomas Monjalon
2013-03-20 16:05 ` [dpdk-dev] [PATCH 12/22] lib: fix unused values Thomas Monjalon
2013-03-20 16:05 ` [dpdk-dev] [PATCH 13/22] lib: fix uninitialized variables Thomas Monjalon
2013-03-20 16:05 ` [dpdk-dev] [PATCH 14/22] lib: fix non-C99 macros definitions in exported headers Thomas Monjalon
2013-03-20 16:05 ` [dpdk-dev] [PATCH 15/22] mem: fix access to huge page with high address Thomas Monjalon
2013-03-20 16:05 ` [dpdk-dev] [PATCH 16/22] timer: check TSC reliability Thomas Monjalon
2013-03-20 16:05 ` [dpdk-dev] [PATCH 17/22] timer: get TSC frequency from /proc/cpuinfo Thomas Monjalon
2013-03-20 16:05 ` [dpdk-dev] [PATCH 18/22] timer: option --vmware-tsc-map for VMware guest Thomas Monjalon
2013-03-20 16:05 ` [dpdk-dev] [PATCH 19/22] pci: reference driver structure for each device Thomas Monjalon
2013-03-20 16:05 ` [dpdk-dev] [PATCH 20/22] pci: allow drivers to be bound several times to the same PCI device Thomas Monjalon
2013-03-20 16:05 ` [dpdk-dev] [PATCH 21/22] igb_uio: fix driver dependency Thomas Monjalon
2013-03-20 16:05 ` [dpdk-dev] [PATCH 22/22] igb_uio: fix build with kernel >= 3.8 Thomas Monjalon
2013-03-20 16:58 ` [dpdk-dev] [PATCH 00/22] upgrade with 6WIND's enhancements Vincent JARDIN
2013-03-21 9:40 ` Thomas Monjalon
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