From: "Gustavo A. R. Silva" <gustavo@embeddedor.com>
To: "Rafael J. Wysocki" <rjw@rjwysocki.net>, Len Brown <lenb@kernel.org>
Cc: linux-acpi@vger.kernel.org, linux-kernel@vger.kernel.org,
"Gustavo A. R. Silva" <garsilva@embeddedor.com>
Subject: [PATCH] ACPI / CPPC: Use 64-bit arithmetic instead of 32-bit
Date: Tue, 6 Feb 2018 17:36:17 -0600 [thread overview]
Message-ID: <20180206233617.GA30829@embeddedgus> (raw)
Add suffix ULL to constant 500 in order to give the compiler complete
information about the proper arithmetic to use. Notice that this
constant is used in a context that expects an expression of type
u64 (64 bits, unsigned).
The expression NUM_RETRIES * cppc_ss->latency at line 578, which at
preprocessing time translates to 500 * cppc_ss->latency is currently
being evaluated using 32-bit arithmetic.
Addresses-Coverity-ID: 1382602
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
---
Notice that another option is to cast NUM_RETRIES to u64 at line 578,
but as there is only one instace in which this macro is being used I
think adding the ULL is just enough.
drivers/acpi/cppc_acpi.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/acpi/cppc_acpi.c b/drivers/acpi/cppc_acpi.c
index 06ea474..0afbb26 100644
--- a/drivers/acpi/cppc_acpi.c
+++ b/drivers/acpi/cppc_acpi.c
@@ -119,7 +119,7 @@ static DEFINE_PER_CPU(struct cpc_desc *, cpc_desc_ptr);
* to PCC commands. Keeping it high enough to cover emulators where
* the processors run painfully slow.
*/
-#define NUM_RETRIES 500
+#define NUM_RETRIES 500ULL
struct cppc_attr {
struct attribute attr;
--
2.7.4
next reply other threads:[~2018-02-06 23:36 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-02-06 23:36 Gustavo A. R. Silva [this message]
2018-02-08 9:49 ` [PATCH] ACPI / CPPC: Use 64-bit arithmetic instead of 32-bit Rafael J. Wysocki
2018-02-08 16:40 ` Gustavo A. R. Silva
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20180206233617.GA30829@embeddedgus \
--to=gustavo@embeddedor.com \
--cc=garsilva@embeddedor.com \
--cc=lenb@kernel.org \
--cc=linux-acpi@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=rjw@rjwysocki.net \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.