From mboxrd@z Thu Jan 1 00:00:00 1970 From: Milo Kim Subject: [PATCH 04/10] leds: lp5521: remove unnecessary writing commands Date: Thu, 8 Aug 2013 16:59:48 +0900 Message-ID: <1375948794-6286-5-git-send-email-milo.kim@ti.com> References: <1375948794-6286-1-git-send-email-milo.kim@ti.com> Return-path: In-Reply-To: <1375948794-6286-1-git-send-email-milo.kim@ti.com> Sender: linux-kernel-owner@vger.kernel.org To: Bryan Wu Cc: =?UTF-8?q?Pali=20Roh=C3=A1r?= , linux-leds@vger.kernel.org, linux-kernel@vger.kernel.org, Milo Kim List-Id: linux-leds@vger.kernel.org This patch reduces the number of programming commands. (Count of sending commands) Old code: 32 + program size (32 counts for clearing program memory) New code: 32 Pattern buffer is initialized to 0 in this function. Just update new program data and remaining buffers are filled with 0. So it's needless to clear whole area. Signed-off-by: Milo Kim --- drivers/leds/leds-lp5521.c | 14 +++----------- 1 file changed, 3 insertions(+), 11 deletions(-) diff --git a/drivers/leds/leds-lp5521.c b/drivers/leds/leds-lp5521.c index c00f922..0518835 100644 --- a/drivers/leds/leds-lp5521.c +++ b/drivers/leds/leds-lp5521.c @@ -220,17 +220,11 @@ static int lp5521_update_program_memory(struct lp55xx_chip *chip, }; unsigned cmd; char c[3]; - int program_size; int nrchars; - int offset = 0; int ret; - int i; - - /* clear program memory before updating */ - for (i = 0; i < LP5521_PROGRAM_LENGTH; i++) - lp55xx_write(chip, addr[idx] + i, 0); + int offset = 0; + int i = 0; - i = 0; while ((offset < size - 1) && (i < LP5521_PROGRAM_LENGTH)) { /* separate sscanfs because length is working only for %s */ ret = sscanf(data + offset, "%2s%n ", c, &nrchars); @@ -250,11 +244,9 @@ static int lp5521_update_program_memory(struct lp55xx_chip *chip, if (i % 2) goto err; - program_size = i; - mutex_lock(&chip->lock); - for (i = 0; i < program_size; i++) { + for (i = 0; i < LP5521_PROGRAM_LENGTH; i++) { ret = lp55xx_write(chip, addr[idx] + i, pattern[i]); if (ret) { mutex_unlock(&chip->lock); -- 1.7.9.5