Author: ian
Date: Sun Mar 18 16:36:14 2018
New Revision: 331129
URL: https://svnweb.freebsd.org/changeset/base/331129
Log:
Eliminate some unneeded intermediate variables. Eliminate some redundant
parens in shift-and-mask expressions. Reword and reflow some comments.
Modified:
head/sys/dev/flash/mx25l.c
Modified: head/sys/dev/flash/mx25l.c
==============================================================================
--- head/sys/dev/flash/mx25l.c Sun Mar 18 16:35:40 2018 (r331128)
+++ head/sys/dev/flash/mx25l.c Sun Mar 18 16:36:14 2018 (r331129)
@@ -280,8 +280,7 @@ mx25l_write(device_t dev, off_t offset, caddr_t data,
struct mx25l_softc *sc;
uint8_t txBuf[8], rxBuf[8];
struct spi_command cmd;
- off_t write_offset;
- long bytes_to_write, bytes_writen;
+ off_t bytes_to_write;
device_t pdev;
int err = 0;
@@ -296,9 +295,6 @@ mx25l_write(device_t dev, off_t offset, caddr_t data,
cmd.rx_cmd_sz = 4;
}
- bytes_writen = 0;
- write_offset = offset;
-
/*
* Writes must be aligned to the erase sectorsize, since blocks are
* fully erased before they're written to.
@@ -307,43 +303,37 @@ mx25l_write(device_t dev, off_t offset, caddr_t data,
return (EIO);
/*
- * Maximum write size for CMD_PAGE_PROGRAM is
- * FLASH_PAGE_SIZE, so split data to chunks
- * FLASH_PAGE_SIZE bytes eash and write them
- * one by one
+ * Maximum write size for CMD_PAGE_PROGRAM is FLASH_PAGE_SIZE, so loop
+ * to write chunks of FLASH_PAGE_SIZE bytes each.
*/
- while (bytes_writen < count) {
- /*
- * If we crossed sector boundary - erase next sector
- */
- if (((offset + bytes_writen) % sc->sc_sectorsize) == 0)
- mx25l_erase_cmd(dev, offset + bytes_writen,
CMD_SECTOR_ERASE);
+ while (count != 0) {
+ /* If we crossed a sector boundary, erase the next sector. */
+ if (((offset) % sc->sc_sectorsize) == 0)
+ mx25l_erase_cmd(dev, offset, CMD_SECTOR_ERASE);
txBuf[0] = CMD_PAGE_PROGRAM;
if (sc->sc_flags & FL_ENABLE_4B_ADDR) {
- txBuf[1] = ((write_offset >> 24) & 0xff);
- txBuf[2] = ((write_offset >> 16) & 0xff);
- txBuf[3] = ((write_offset >> 8) & 0xff);
- txBuf[4] = (write_offset & 0xff);
+ txBuf[1] = (offset >> 24) & 0xff;
+ txBuf[2] = (offset >> 16) & 0xff;
+ txBuf[3] = (offset >> 8) & 0xff;
+ txBuf[4] = offset & 0xff;
} else {
- txBuf[1] = ((write_offset >> 16) & 0xff);
- txBuf[2] = ((write_offset >> 8) & 0xff);
- txBuf[3] = (write_offset & 0xff);
+ txBuf[1] = (offset >> 16) & 0xff;
+ txBuf[2] = (offset >> 8) & 0xff;
+ txBuf[3] = offset & 0xff;
}
- bytes_to_write = MIN(FLASH_PAGE_SIZE,
- count - bytes_writen);
+ bytes_to_write = MIN(FLASH_PAGE_SIZE, count);
cmd.tx_cmd = txBuf;
cmd.rx_cmd = rxBuf;
- cmd.tx_data = data + bytes_writen;
- cmd.tx_data_sz = bytes_to_write;
+ cmd.tx_data = data;
cmd.rx_data = sc->sc_dummybuf;
- cmd.rx_data_sz = bytes_to_write;
+ cmd.tx_data_sz = (uint32_t)bytes_to_write;
+ cmd.rx_data_sz = (uint32_t)bytes_to_write;
/*
- * Eash completed write operation resets WEL
- * (write enable latch) to disabled state,
- * so we re-enable it here
+ * Each completed write operation resets WEL (write enable
+ * latch) to disabled state, so we re-enable it here.
*/
mx25l_wait_for_device_ready(dev);
mx25l_set_writable(dev, 1);
@@ -352,8 +342,9 @@ mx25l_write(device_t dev, off_t offset, caddr_t data,
if (err)
break;
- bytes_writen += bytes_to_write;
- write_offset += bytes_to_write;
+ data += bytes_to_write;
+ offset += bytes_to_write;
+ count -= bytes_to_write;
}
return (err);
@@ -372,12 +363,12 @@ mx25l_read(device_t dev, off_t offset, caddr_t data, o
sc = device_get_softc(dev);
/*
- * Enforce the disk read sectorsize not the erase sectorsize.
- * In this way, smaller read IO is possible,dramatically
- * speeding up filesystem/geom_compress access.
+ * Enforce that reads are aligned to the disk sectorsize, not the
+ * erase sectorsize. In this way, smaller read IO is possible,
+ * dramatically speeding up filesystem/geom_compress access.
*/
- if (count % sc->sc_disk->d_sectorsize != 0
- || offset % sc->sc_disk->d_sectorsize != 0)
+ if (count % sc->sc_disk->d_sectorsize != 0 ||
+ offset % sc->sc_disk->d_sectorsize != 0)
return (EIO);
txBuf[0] = CMD_FAST_READ;
@@ -385,19 +376,19 @@ mx25l_read(device_t dev, off_t offset, caddr_t data, o
cmd.tx_cmd_sz = 6;
cmd.rx_cmd_sz = 6;
- txBuf[1] = ((offset >> 24) & 0xff);
- txBuf[2] = ((offset >> 16) & 0xff);
- txBuf[3] = ((offset >> 8) & 0xff);
- txBuf[4] = (offset & 0xff);
+ txBuf[1] = (offset >> 24) & 0xff;
+ txBuf[2] = (offset >> 16) & 0xff;
+ txBuf[3] = (offset >> 8) & 0xff;
+ txBuf[4] = offset & 0xff;
/* Dummy byte */
txBuf[5] = 0;
} else {
cmd.tx_cmd_sz = 5;
cmd.rx_cmd_sz = 5;
- txBuf[1] = ((offset >> 16) & 0xff);
- txBuf[2] = ((offset >> 8) & 0xff);
- txBuf[3] = (offset & 0xff);
+ txBuf[1] = (offset >> 16) & 0xff;
+ txBuf[2] = (offset >> 8) & 0xff;
+ txBuf[3] = offset & 0xff;
/* Dummy byte */
txBuf[4] = 0;
}
@@ -405,8 +396,8 @@ mx25l_read(device_t dev, off_t offset, caddr_t data, o
cmd.tx_cmd = txBuf;
cmd.rx_cmd = rxBuf;
cmd.tx_data = data;
- cmd.tx_data_sz = count;
cmd.rx_data = data;
+ cmd.tx_data_sz = count;
cmd.rx_data_sz = count;
err = SPIBUS_TRANSFER(pdev, dev, &cmd);
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