linux-kernel - [PATCH 2/2 V2] staging: atomisp: use local variable to reduce the number of reference

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Message-ID: <20170331013012.GA15884@jyoun-Latitude-E6530>
Date:   Fri, 31 Mar 2017 10:30:12 +0900
From:   Daeseok Youn <daeseok.youn@...il.com>
To:     mchehab@...nel.org
Cc:     gregkh@...uxfoundation.org, daeseok.youn@...il.com,
        alan@...ux.intel.com, dan.carpenter@...cle.com,
        singhalsimran0@...il.com, linux-media@...r.kernel.org,
        devel@...verdev.osuosl.org, linux-kernel@...r.kernel.org,
        kernel-janitors@...r.kernel.org
Subject: [PATCH 2/2 V2] staging: atomisp: use local variable to reduce the
 number of reference

Define new local variable to reduce the number of reference.
The new local variable is added to save the addess of dfs
and used in atomisp_freq_scaling() function.

Signed-off-by: Daeseok Youn <daeseok.youn@...il.com>
---
V2: this patch was rebased since the patch 1/2 was improved.

 .../media/atomisp/pci/atomisp2/atomisp_cmd.c       | 37 ++++++++++++----------
 1 file changed, 20 insertions(+), 17 deletions(-)

diff --git a/drivers/staging/media/atomisp/pci/atomisp2/atomisp_cmd.c b/drivers/staging/media/atomisp/pci/atomisp2/atomisp_cmd.c
index 87224d6..9f4041a 100644
--- a/drivers/staging/media/atomisp/pci/atomisp2/atomisp_cmd.c
+++ b/drivers/staging/media/atomisp/pci/atomisp2/atomisp_cmd.c
@@ -251,6 +251,7 @@ int atomisp_freq_scaling(struct atomisp_device *isp,
 {
 	/* FIXME! Only use subdev[0] status yet */
 	struct atomisp_sub_device *asd = &isp->asd[0];
+	const struct atomisp_dfs_config *dfs;
 	unsigned int new_freq;
 	struct atomisp_freq_scaling_rule curr_rules;
 	int i, ret;
@@ -264,20 +265,22 @@ int atomisp_freq_scaling(struct atomisp_device *isp,
 	if (ATOMISP_IS_CHT(isp) && ATOMISP_USE_YUVPP(asd))
 		isp->dfs = &dfs_config_cht_soc;
 
-	if (isp->dfs->lowest_freq == 0 || isp->dfs->max_freq_at_vmin == 0 ||
-	    isp->dfs->highest_freq == 0 || isp->dfs->dfs_table_size == 0 ||
-	    !isp->dfs->dfs_table) {
+	dfs = isp->dfs;
+
+	if (dfs->lowest_freq == 0 || dfs->max_freq_at_vmin == 0 ||
+	    dfs->highest_freq == 0 || dfs->dfs_table_size == 0 ||
+	    !dfs->dfs_table) {
 		dev_err(isp->dev, "DFS configuration is invalid.\n");
 		return -EINVAL;
 	}
 
 	if (mode == ATOMISP_DFS_MODE_LOW) {
-		new_freq = isp->dfs->lowest_freq;
+		new_freq = dfs->lowest_freq;
 		goto done;
 	}
 
 	if (mode == ATOMISP_DFS_MODE_MAX) {
-		new_freq = isp->dfs->highest_freq;
+		new_freq = dfs->highest_freq;
 		goto done;
 	}
 
@@ -303,26 +306,26 @@ int atomisp_freq_scaling(struct atomisp_device *isp,
 	}
 
 	/* search for the target frequency by looping freq rules*/
-	for (i = 0; i < isp->dfs->dfs_table_size; i++) {
-		if (curr_rules.width != isp->dfs->dfs_table[i].width &&
-		    isp->dfs->dfs_table[i].width != ISP_FREQ_RULE_ANY)
+	for (i = 0; i < dfs->dfs_table_size; i++) {
+		if (curr_rules.width != dfs->dfs_table[i].width &&
+		    dfs->dfs_table[i].width != ISP_FREQ_RULE_ANY)
 			continue;
-		if (curr_rules.height != isp->dfs->dfs_table[i].height &&
-		    isp->dfs->dfs_table[i].height != ISP_FREQ_RULE_ANY)
+		if (curr_rules.height != dfs->dfs_table[i].height &&
+		    dfs->dfs_table[i].height != ISP_FREQ_RULE_ANY)
 			continue;
-		if (curr_rules.fps != isp->dfs->dfs_table[i].fps &&
-		    isp->dfs->dfs_table[i].fps != ISP_FREQ_RULE_ANY)
+		if (curr_rules.fps != dfs->dfs_table[i].fps &&
+		    dfs->dfs_table[i].fps != ISP_FREQ_RULE_ANY)
 			continue;
-		if (curr_rules.run_mode != isp->dfs->dfs_table[i].run_mode &&
-		    isp->dfs->dfs_table[i].run_mode != ISP_FREQ_RULE_ANY)
+		if (curr_rules.run_mode != dfs->dfs_table[i].run_mode &&
+		    dfs->dfs_table[i].run_mode != ISP_FREQ_RULE_ANY)
 			continue;
 		break;
 	}
 
-	if (i == isp->dfs->dfs_table_size)
-		new_freq = isp->dfs->max_freq_at_vmin;
+	if (i == dfs->dfs_table_size)
+		new_freq = dfs->max_freq_at_vmin;
 	else
-		new_freq = isp->dfs->dfs_table[i].isp_freq;
+		new_freq = dfs->dfs_table[i].isp_freq;
 
 done:
 	dev_dbg(isp->dev, "DFS target frequency=%d.\n", new_freq);
-- 
2.7.4