From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrew Morton Subject: Re: [PATCH 2/2] rtc: driver for Conexant Digicolor CX92755 on-chip RTC Date: Mon, 23 Mar 2015 15:33:34 -0700 Message-ID: <20150323153334.a373431dd5af6b669f716d83@linux-foundation.org> References: <374ef109005ed14c3a0052a9da5226b87f8dc215.1427117334.git.baruch@tkos.co.il> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <374ef109005ed14c3a0052a9da5226b87f8dc215.1427117334.git.baruch-NswTu9S1W3P6gbPvEgmw2w@public.gmane.org> Sender: devicetree-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Baruch Siach Cc: Alessandro Zummo , rtc-linux-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org, linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: devicetree@vger.kernel.org On Mon, 23 Mar 2015 15:28:54 +0200 Baruch Siach 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 From mboxrd@z Thu Jan 1 00:00:00 1970 From: akpm@linux-foundation.org (Andrew Morton) Date: Mon, 23 Mar 2015 15:33:34 -0700 Subject: [PATCH 2/2] rtc: driver for Conexant Digicolor CX92755 on-chip RTC In-Reply-To: <374ef109005ed14c3a0052a9da5226b87f8dc215.1427117334.git.baruch@tkos.co.il> References: <374ef109005ed14c3a0052a9da5226b87f8dc215.1427117334.git.baruch@tkos.co.il> Message-ID: <20150323153334.a373431dd5af6b669f716d83@linux-foundation.org> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Mon, 23 Mar 2015 15:28:54 +0200 Baruch Siach 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