[PATCH] mmc: use empty initializer list to zero-clear structures

* [PATCH] mmc: use empty initializer list to zero-clear structures
@ 2016-12-19 11:51 Masahiro Yamada
  2016-12-30  8:09 ` Linus Walleij
  2017-01-10 15:38 ` Ulf Hansson
  0 siblings, 2 replies; 3+ messages in thread
From: Masahiro Yamada @ 2016-12-19 11:51 UTC (permalink / raw)
  To: linux-mmc
  Cc: Masahiro Yamada, Tejun Heo, Baolin Wang, Bojan Prtvar,
	Adrian Hunter, Russell King, Pratibhasagar V, Gwendal Grignou,
	Linus Walleij, Jens Axboe, linux-kernel, Jaehoon Chung,
	Dong Aisheng, Chaotian Jing, Wolfram Sang, Shawn Lin,
	Dan Carpenter, Bhaktipriya Shridhar, Ulf Hansson

In the MMC subsystem, we see such initializers that only clears the
first member explicitly.

For example,

  struct mmc_request mrq = {NULL};

sets the first member (.sbc) to NULL explicitly.  However, this is
an unstable form because we may insert a non-pointer member at the
top of the struct mmc_request in the future. (if we do so, the
compiler will spit warnings.)

So, using a designated initializer is preferred coding style.  The
expression above is equivalent to:

  struct mmc_request mrq = { .sbc = NULL };

Of course, this does not express our intention.  We want to fill
all struct members with zeros.  Please note struct members are
implicitly zero-cleared unless otherwise specified in the initializer.

After all, the most reasonable (and stable) form is:

  struct mmc_request mrq = {};

Do likewise for mmc_command, mmc_data as well.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
---

 drivers/mmc/core/block.c          | 16 +++++++-------
 drivers/mmc/core/core.c           | 10 ++++-----
 drivers/mmc/core/mmc.c            |  2 +-
 drivers/mmc/core/mmc_ops.c        | 44 +++++++++++++++++++--------------------
 drivers/mmc/core/mmc_test.c       | 26 +++++++++++------------
 drivers/mmc/core/sd_ops.c         | 30 +++++++++++++-------------
 drivers/mmc/core/sdio_ops.c       | 10 ++++-----
 drivers/mmc/host/rtsx_pci_sdmmc.c |  2 +-
 drivers/mmc/host/rtsx_usb_sdmmc.c |  2 +-
 drivers/mmc/host/sdhci.c          |  4 ++--
 10 files changed, 73 insertions(+), 73 deletions(-)

diff --git a/drivers/mmc/core/block.c b/drivers/mmc/core/block.c
index bab3f07..82764786d 100644
--- a/drivers/mmc/core/block.c
+++ b/drivers/mmc/core/block.c
@@ -442,9 +442,9 @@ static int ioctl_do_sanitize(struct mmc_card *card)
 static int __mmc_blk_ioctl_cmd(struct mmc_card *card, struct mmc_blk_data *md,
 			       struct mmc_blk_ioc_data *idata)
 {
-	struct mmc_command cmd = {0};
-	struct mmc_data data = {0};
-	struct mmc_request mrq = {NULL};
+	struct mmc_command cmd = {};
+	struct mmc_data data = {};
+	struct mmc_request mrq = {};
 	struct scatterlist sg;
 	int err;
 	int is_rpmb = false;
@@ -768,9 +768,9 @@ static u32 mmc_sd_num_wr_blocks(struct mmc_card *card)
 	u32 result;
 	__be32 *blocks;
 
-	struct mmc_request mrq = {NULL};
-	struct mmc_command cmd = {0};
-	struct mmc_data data = {0};
+	struct mmc_request mrq = {};
+	struct mmc_command cmd = {};
+	struct mmc_data data = {};
 
 	struct scatterlist sg;
 
@@ -819,7 +819,7 @@ static u32 mmc_sd_num_wr_blocks(struct mmc_card *card)
 
 static int get_card_status(struct mmc_card *card, u32 *status, int retries)
 {
-	struct mmc_command cmd = {0};
+	struct mmc_command cmd = {};
 	int err;
 
 	cmd.opcode = MMC_SEND_STATUS;
@@ -884,7 +884,7 @@ static int send_stop(struct mmc_card *card, unsigned int timeout_ms,
 		struct request *req, bool *gen_err, u32 *stop_status)
 {
 	struct mmc_host *host = card->host;
-	struct mmc_command cmd = {0};
+	struct mmc_command cmd = {};
 	int err;
 	bool use_r1b_resp = rq_data_dir(req) == WRITE;
 
diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
index 543eadd..047f672 100644
--- a/drivers/mmc/core/core.c
+++ b/drivers/mmc/core/core.c
@@ -809,7 +809,7 @@ EXPORT_SYMBOL(mmc_interrupt_hpi);
  */
 int mmc_wait_for_cmd(struct mmc_host *host, struct mmc_command *cmd, int retries)
 {
-	struct mmc_request mrq = {NULL};
+	struct mmc_request mrq = {};
 
 	WARN_ON(!host->claimed);
 
@@ -1650,7 +1650,7 @@ int __mmc_set_signal_voltage(struct mmc_host *host, int signal_voltage)
 
 int mmc_set_signal_voltage(struct mmc_host *host, int signal_voltage, u32 ocr)
 {
-	struct mmc_command cmd = {0};
+	struct mmc_command cmd = {};
 	int err = 0;
 	u32 clock;
 
@@ -2131,7 +2131,7 @@ static unsigned int mmc_erase_timeout(struct mmc_card *card,
 static int mmc_do_erase(struct mmc_card *card, unsigned int from,
 			unsigned int to, unsigned int arg)
 {
-	struct mmc_command cmd = {0};
+	struct mmc_command cmd = {};
 	unsigned int qty = 0, busy_timeout = 0;
 	bool use_r1b_resp = false;
 	unsigned long timeout;
@@ -2553,7 +2553,7 @@ EXPORT_SYMBOL(mmc_calc_max_discard);
 
 int mmc_set_blocklen(struct mmc_card *card, unsigned int blocklen)
 {
-	struct mmc_command cmd = {0};
+	struct mmc_command cmd = {};
 
 	if (mmc_card_blockaddr(card) || mmc_card_ddr52(card) ||
 	    mmc_card_hs400(card) || mmc_card_hs400es(card))
@@ -2569,7 +2569,7 @@ EXPORT_SYMBOL(mmc_set_blocklen);
 int mmc_set_blockcount(struct mmc_card *card, unsigned int blockcount,
 			bool is_rel_write)
 {
-	struct mmc_command cmd = {0};
+	struct mmc_command cmd = {};
 
 	cmd.opcode = MMC_SET_BLOCK_COUNT;
 	cmd.arg = blockcount & 0x0000FFFF;
diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c
index b61b52f9..f4d1b52 100644
--- a/drivers/mmc/core/mmc.c
+++ b/drivers/mmc/core/mmc.c
@@ -1805,7 +1805,7 @@ static int mmc_can_sleep(struct mmc_card *card)
 
 static int mmc_sleep(struct mmc_host *host)
 {
-	struct mmc_command cmd = {0};
+	struct mmc_command cmd = {};
 	struct mmc_card *card = host->card;
 	unsigned int timeout_ms = DIV_ROUND_UP(card->ext_csd.sa_timeout, 10000);
 	int err;
diff --git a/drivers/mmc/core/mmc_ops.c b/drivers/mmc/core/mmc_ops.c
index b11c345..db2969f 100644
--- a/drivers/mmc/core/mmc_ops.c
+++ b/drivers/mmc/core/mmc_ops.c
@@ -57,7 +57,7 @@ static const u8 tuning_blk_pattern_8bit[] = {
 int mmc_send_status(struct mmc_card *card, u32 *status)
 {
 	int err;
-	struct mmc_command cmd = {0};
+	struct mmc_command cmd = {};
 
 	cmd.opcode = MMC_SEND_STATUS;
 	if (!mmc_host_is_spi(card->host))
@@ -79,7 +79,7 @@ int mmc_send_status(struct mmc_card *card, u32 *status)
 
 static int _mmc_select_card(struct mmc_host *host, struct mmc_card *card)
 {
-	struct mmc_command cmd = {0};
+	struct mmc_command cmd = {};
 
 	cmd.opcode = MMC_SELECT_CARD;
 
@@ -115,7 +115,7 @@ int mmc_deselect_cards(struct mmc_host *host)
  */
 int mmc_set_dsr(struct mmc_host *host)
 {
-	struct mmc_command cmd = {0};
+	struct mmc_command cmd = {};
 
 	cmd.opcode = MMC_SET_DSR;
 
@@ -128,7 +128,7 @@ int mmc_set_dsr(struct mmc_host *host)
 int mmc_go_idle(struct mmc_host *host)
 {
 	int err;
-	struct mmc_command cmd = {0};
+	struct mmc_command cmd = {};
 
 	/*
 	 * Non-SPI hosts need to prevent chipselect going active during
@@ -164,7 +164,7 @@ int mmc_go_idle(struct mmc_host *host)
 
 int mmc_send_op_cond(struct mmc_host *host, u32 ocr, u32 *rocr)
 {
-	struct mmc_command cmd = {0};
+	struct mmc_command cmd = {};
 	int i, err = 0;
 
 	cmd.opcode = MMC_SEND_OP_COND;
@@ -203,7 +203,7 @@ int mmc_send_op_cond(struct mmc_host *host, u32 ocr, u32 *rocr)
 int mmc_all_send_cid(struct mmc_host *host, u32 *cid)
 {
 	int err;
-	struct mmc_command cmd = {0};
+	struct mmc_command cmd = {};
 
 	cmd.opcode = MMC_ALL_SEND_CID;
 	cmd.arg = 0;
@@ -220,7 +220,7 @@ int mmc_all_send_cid(struct mmc_host *host, u32 *cid)
 
 int mmc_set_relative_addr(struct mmc_card *card)
 {
-	struct mmc_command cmd = {0};
+	struct mmc_command cmd = {};
 
 	cmd.opcode = MMC_SET_RELATIVE_ADDR;
 	cmd.arg = card->rca << 16;
@@ -233,7 +233,7 @@ static int
 mmc_send_cxd_native(struct mmc_host *host, u32 arg, u32 *cxd, int opcode)
 {
 	int err;
-	struct mmc_command cmd = {0};
+	struct mmc_command cmd = {};
 
 	cmd.opcode = opcode;
 	cmd.arg = arg;
@@ -256,9 +256,9 @@ static int
 mmc_send_cxd_data(struct mmc_card *card, struct mmc_host *host,
 		u32 opcode, void *buf, unsigned len)
 {
-	struct mmc_request mrq = {NULL};
-	struct mmc_command cmd = {0};
-	struct mmc_data data = {0};
+	struct mmc_request mrq = {};
+	struct mmc_command cmd = {};
+	struct mmc_data data = {};
 	struct scatterlist sg;
 
 	mrq.cmd = &cmd;
@@ -387,7 +387,7 @@ EXPORT_SYMBOL_GPL(mmc_get_ext_csd);
 
 int mmc_spi_read_ocr(struct mmc_host *host, int highcap, u32 *ocrp)
 {
-	struct mmc_command cmd = {0};
+	struct mmc_command cmd = {};
 	int err;
 
 	cmd.opcode = MMC_SPI_READ_OCR;
@@ -402,7 +402,7 @@ int mmc_spi_read_ocr(struct mmc_host *host, int highcap, u32 *ocrp)
 
 int mmc_spi_set_crc(struct mmc_host *host, int use_crc)
 {
-	struct mmc_command cmd = {0};
+	struct mmc_command cmd = {};
 	int err;
 
 	cmd.opcode = MMC_SPI_CRC_ON_OFF;
@@ -533,7 +533,7 @@ int __mmc_switch(struct mmc_card *card, u8 set, u8 index, u8 value,
 {
 	struct mmc_host *host = card->host;
 	int err;
-	struct mmc_command cmd = {0};
+	struct mmc_command cmd = {};
 	bool use_r1b_resp = use_busy_signal;
 	unsigned char old_timing = host->ios.timing;
 
@@ -611,9 +611,9 @@ EXPORT_SYMBOL_GPL(mmc_switch);
 
 int mmc_send_tuning(struct mmc_host *host, u32 opcode, int *cmd_error)
 {
-	struct mmc_request mrq = {NULL};
-	struct mmc_command cmd = {0};
-	struct mmc_data data = {0};
+	struct mmc_request mrq = {};
+	struct mmc_command cmd = {};
+	struct mmc_data data = {};
 	struct scatterlist sg;
 	struct mmc_ios *ios = &host->ios;
 	const u8 *tuning_block_pattern;
@@ -680,7 +680,7 @@ EXPORT_SYMBOL_GPL(mmc_send_tuning);
 
 int mmc_abort_tuning(struct mmc_host *host, u32 opcode)
 {
-	struct mmc_command cmd = {0};
+	struct mmc_command cmd = {};
 
 	/*
 	 * eMMC specification specifies that CMD12 can be used to stop a tuning
@@ -707,9 +707,9 @@ static int
 mmc_send_bus_test(struct mmc_card *card, struct mmc_host *host, u8 opcode,
 		  u8 len)
 {
-	struct mmc_request mrq = {NULL};
-	struct mmc_command cmd = {0};
-	struct mmc_data data = {0};
+	struct mmc_request mrq = {};
+	struct mmc_command cmd = {};
+	struct mmc_data data = {};
 	struct scatterlist sg;
 	u8 *data_buf;
 	u8 *test_buf;
@@ -803,7 +803,7 @@ int mmc_bus_test(struct mmc_card *card, u8 bus_width)
 
 int mmc_send_hpi_cmd(struct mmc_card *card, u32 *status)
 {
-	struct mmc_command cmd = {0};
+	struct mmc_command cmd = {};
 	unsigned int opcode;
 	int err;
 
diff --git a/drivers/mmc/core/mmc_test.c b/drivers/mmc/core/mmc_test.c
index 3ab6e52..bd8eb9b 100644
--- a/drivers/mmc/core/mmc_test.c
+++ b/drivers/mmc/core/mmc_test.c
@@ -260,7 +260,7 @@ static int mmc_test_busy(struct mmc_command *cmd)
 static int mmc_test_wait_busy(struct mmc_test_card *test)
 {
 	int ret, busy;
-	struct mmc_command cmd = {0};
+	struct mmc_command cmd = {};
 
 	busy = 0;
 	do {
@@ -292,10 +292,10 @@ static int mmc_test_wait_busy(struct mmc_test_card *test)
 static int mmc_test_buffer_transfer(struct mmc_test_card *test,
 	u8 *buffer, unsigned addr, unsigned blksz, int write)
 {
-	struct mmc_request mrq = {0};
-	struct mmc_command cmd = {0};
-	struct mmc_command stop = {0};
-	struct mmc_data data = {0};
+	struct mmc_request mrq = {};
+	struct mmc_command cmd = {};
+	struct mmc_command stop = {};
+	struct mmc_data data = {};
 
 	struct scatterlist sg;
 
@@ -885,10 +885,10 @@ static int mmc_test_simple_transfer(struct mmc_test_card *test,
 	struct scatterlist *sg, unsigned sg_len, unsigned dev_addr,
 	unsigned blocks, unsigned blksz, int write)
 {
-	struct mmc_request mrq = {0};
-	struct mmc_command cmd = {0};
-	struct mmc_command stop = {0};
-	struct mmc_data data = {0};
+	struct mmc_request mrq = {};
+	struct mmc_command cmd = {};
+	struct mmc_command stop = {};
+	struct mmc_data data = {};
 
 	mrq.cmd = &cmd;
 	mrq.data = &data;
@@ -910,10 +910,10 @@ static int mmc_test_simple_transfer(struct mmc_test_card *test,
 static int mmc_test_broken_transfer(struct mmc_test_card *test,
 	unsigned blocks, unsigned blksz, int write)
 {
-	struct mmc_request mrq = {0};
-	struct mmc_command cmd = {0};
-	struct mmc_command stop = {0};
-	struct mmc_data data = {0};
+	struct mmc_request mrq = {};
+	struct mmc_command cmd = {};
+	struct mmc_command stop = {};
+	struct mmc_data data = {};
 
 	struct scatterlist sg;
 
diff --git a/drivers/mmc/core/sd_ops.c b/drivers/mmc/core/sd_ops.c
index de125a4..9d5824a 100644
--- a/drivers/mmc/core/sd_ops.c
+++ b/drivers/mmc/core/sd_ops.c
@@ -25,7 +25,7 @@
 int mmc_app_cmd(struct mmc_host *host, struct mmc_card *card)
 {
 	int err;
-	struct mmc_command cmd = {0};
+	struct mmc_command cmd = {};
 
 	if (WARN_ON(card && card->host != host))
 		return -EINVAL;
@@ -68,7 +68,7 @@ EXPORT_SYMBOL_GPL(mmc_app_cmd);
 int mmc_wait_for_app_cmd(struct mmc_host *host, struct mmc_card *card,
 	struct mmc_command *cmd, int retries)
 {
-	struct mmc_request mrq = {NULL};
+	struct mmc_request mrq = {};
 
 	int i, err;
 
@@ -120,7 +120,7 @@ EXPORT_SYMBOL(mmc_wait_for_app_cmd);
 
 int mmc_app_set_bus_width(struct mmc_card *card, int width)
 {
-	struct mmc_command cmd = {0};
+	struct mmc_command cmd = {};
 
 	cmd.opcode = SD_APP_SET_BUS_WIDTH;
 	cmd.flags = MMC_RSP_R1 | MMC_CMD_AC;
@@ -141,7 +141,7 @@ int mmc_app_set_bus_width(struct mmc_card *card, int width)
 
 int mmc_send_app_op_cond(struct mmc_host *host, u32 ocr, u32 *rocr)
 {
-	struct mmc_command cmd = {0};
+	struct mmc_command cmd = {};
 	int i, err = 0;
 
 	cmd.opcode = SD_APP_OP_COND;
@@ -185,7 +185,7 @@ int mmc_send_app_op_cond(struct mmc_host *host, u32 ocr, u32 *rocr)
 
 int mmc_send_if_cond(struct mmc_host *host, u32 ocr)
 {
-	struct mmc_command cmd = {0};
+	struct mmc_command cmd = {};
 	int err;
 	static const u8 test_pattern = 0xAA;
 	u8 result_pattern;
@@ -217,7 +217,7 @@ int mmc_send_if_cond(struct mmc_host *host, u32 ocr)
 int mmc_send_relative_addr(struct mmc_host *host, unsigned int *rca)
 {
 	int err;
-	struct mmc_command cmd = {0};
+	struct mmc_command cmd = {};
 
 	cmd.opcode = SD_SEND_RELATIVE_ADDR;
 	cmd.arg = 0;
@@ -235,9 +235,9 @@ int mmc_send_relative_addr(struct mmc_host *host, unsigned int *rca)
 int mmc_app_send_scr(struct mmc_card *card, u32 *scr)
 {
 	int err;
-	struct mmc_request mrq = {NULL};
-	struct mmc_command cmd = {0};
-	struct mmc_data data = {0};
+	struct mmc_request mrq = {};
+	struct mmc_command cmd = {};
+	struct mmc_data data = {};
 	struct scatterlist sg;
 	void *data_buf;
 
@@ -290,9 +290,9 @@ int mmc_app_send_scr(struct mmc_card *card, u32 *scr)
 int mmc_sd_switch(struct mmc_card *card, int mode, int group,
 	u8 value, u8 *resp)
 {
-	struct mmc_request mrq = {NULL};
-	struct mmc_command cmd = {0};
-	struct mmc_data data = {0};
+	struct mmc_request mrq = {};
+	struct mmc_command cmd = {};
+	struct mmc_data data = {};
 	struct scatterlist sg;
 
 	/* NOTE: caller guarantees resp is heap-allocated */
@@ -332,9 +332,9 @@ int mmc_sd_switch(struct mmc_card *card, int mode, int group,
 int mmc_app_sd_status(struct mmc_card *card, void *ssr)
 {
 	int err;
-	struct mmc_request mrq = {NULL};
-	struct mmc_command cmd = {0};
-	struct mmc_data data = {0};
+	struct mmc_request mrq = {};
+	struct mmc_command cmd = {};
+	struct mmc_data data = {};
 	struct scatterlist sg;
 
 	/* NOTE: caller guarantees ssr is heap-allocated */
diff --git a/drivers/mmc/core/sdio_ops.c b/drivers/mmc/core/sdio_ops.c
index 90fe554..3c0d3ab 100644
--- a/drivers/mmc/core/sdio_ops.c
+++ b/drivers/mmc/core/sdio_ops.c
@@ -21,7 +21,7 @@
 
 int mmc_send_io_op_cond(struct mmc_host *host, u32 ocr, u32 *rocr)
 {
-	struct mmc_command cmd = {0};
+	struct mmc_command cmd = {};
 	int i, err = 0;
 
 	cmd.opcode = SD_IO_SEND_OP_COND;
@@ -66,7 +66,7 @@ int mmc_send_io_op_cond(struct mmc_host *host, u32 ocr, u32 *rocr)
 static int mmc_io_rw_direct_host(struct mmc_host *host, int write, unsigned fn,
 	unsigned addr, u8 in, u8 *out)
 {
-	struct mmc_command cmd = {0};
+	struct mmc_command cmd = {};
 	int err;
 
 	if (fn > 7)
@@ -118,9 +118,9 @@ int mmc_io_rw_direct(struct mmc_card *card, int write, unsigned fn,
 int mmc_io_rw_extended(struct mmc_card *card, int write, unsigned fn,
 	unsigned addr, int incr_addr, u8 *buf, unsigned blocks, unsigned blksz)
 {
-	struct mmc_request mrq = {NULL};
-	struct mmc_command cmd = {0};
-	struct mmc_data data = {0};
+	struct mmc_request mrq = {};
+	struct mmc_command cmd = {};
+	struct mmc_data data = {};
 	struct scatterlist sg, *sg_ptr;
 	struct sg_table sgtable;
 	unsigned int nents, left_size, i;
diff --git a/drivers/mmc/host/rtsx_pci_sdmmc.c b/drivers/mmc/host/rtsx_pci_sdmmc.c
index ecb99a8..41b5771 100644
--- a/drivers/mmc/host/rtsx_pci_sdmmc.c
+++ b/drivers/mmc/host/rtsx_pci_sdmmc.c
@@ -707,7 +707,7 @@ static int sd_tuning_rx_cmd(struct realtek_pci_sdmmc *host,
 		u8 opcode, u8 sample_point)
 {
 	int err;
-	struct mmc_command cmd = {0};
+	struct mmc_command cmd = {};
 
 	err = sd_change_phase(host, sample_point, true);
 	if (err < 0)
diff --git a/drivers/mmc/host/rtsx_usb_sdmmc.c b/drivers/mmc/host/rtsx_usb_sdmmc.c
index dc1abd1..12d2fbe 100644
--- a/drivers/mmc/host/rtsx_usb_sdmmc.c
+++ b/drivers/mmc/host/rtsx_usb_sdmmc.c
@@ -682,7 +682,7 @@ static int sd_tuning_rx_cmd(struct rtsx_usb_sdmmc *host,
 		u8 opcode, u8 sample_point)
 {
 	int err;
-	struct mmc_command cmd = {0};
+	struct mmc_command cmd = {};
 
 	err = sd_change_phase(host, sample_point, 0);
 	if (err)
diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index 111991e..891f7c6 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -2018,8 +2018,8 @@ static void sdhci_send_tuning(struct sdhci_host *host, u32 opcode,
 			      unsigned long flags)
 {
 	struct mmc_host *mmc = host->mmc;
-	struct mmc_command cmd = {0};
-	struct mmc_request mrq = {NULL};
+	struct mmc_command cmd = {};
+	struct mmc_request mrq = {};
 
 	cmd.opcode = opcode;
 	cmd.flags = MMC_RSP_R1 | MMC_CMD_ADTC;
-- 
2.7.4

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