Re: [PATCH 2/2] rtc: driver for Conexant Digicolor CX92755 on-chip RTC
From: Andrew Morton <hidden>
Date: 2015-03-23 22:33:34
Also in:
linux-arm-kernel
On Mon, 23 Mar 2015 15:28:54 +0200 Baruch Siach [off-list ref] wrote:
Add driver for the RTC hardware block on the Conexant CX92755 SoC, from the
Digicolor series of SoCs. Tested on the Equinox evaluation board for the
CX92755 chip.
...
+static int dc_rtc_read(struct dc_rtc *rtc, unsigned long *val)
+{
+ u8 read_cmds[] = {CMD_READ, CMD_NOP};
+ u32 reference, time1, time2;
+ int ret;
+
+ ret = dc_rtc_cmds(rtc, read_cmds, ARRAY_SIZE(read_cmds));This is asking the compiler to build read_cmds[] on the stack each time dc_rtc_read() is called. If we instead create the array at compile time:
+++ a/drivers/rtc/rtc-digicolor.c@@ -42,7 +42,7 @@ struct dc_rtc { void __iomem *regs; }; -static int dc_rtc_cmds(struct dc_rtc *rtc, u8 *cmds, int len) +static int dc_rtc_cmds(struct dc_rtc *rtc, const u8 *cmds, int len) { u8 val; int i, ret;
@@ -62,7 +62,7 @@ static int dc_rtc_cmds(struct dc_rtc *rt static int dc_rtc_read(struct dc_rtc *rtc, unsigned long *val) { - u8 read_cmds[] = {CMD_READ, CMD_NOP}; + static const u8 read_cmds[] = {CMD_READ, CMD_NOP}; u32 reference, time1, time2; int ret;
@@ -86,7 +86,7 @@ static int dc_rtc_read(struct dc_rtc *rt static int dc_rtc_write(struct dc_rtc *rtc, u32 val) { - u8 write_cmds[] = {CMD_WRITE, CMD_NOP, CMD_RESET, CMD_NOP}; + static const u8 write_cmds[] = {CMD_WRITE, CMD_NOP, CMD_RESET, CMD_NOP}; writel_relaxed(val, rtc->regs + DC_RTC_REFERENCE); return dc_rtc_cmds(rtc, write_cmds, ARRAY_SIZE(write_cmds));
The code gets a bit smaller and faster: text data bss dec hex filename 1628 400 512 2540 9ec drivers/rtc/rtc-digicolor.o-before 1593 400 536 2529 9e1 drivers/rtc/rtc-digicolor.o-after -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html