[PATCH v1] applesmc: Cleanups on top of re-work comms

Brad Campbell
2020-11-11T04:56:09Z

A few small cleanups on top of the comms changes for applesmc.c :

send_byte() is always called with APPLESMC_CMD_PORT, so simplify.
Remove redundant check from smc_sane().
Consolidate writing length with other setup parameters.
Consolidate read and write error messages to a single statement each.

Length and error consolidation suggested by Henrik Rydberg <rydberg@bitmath.org>

Signed-off-by: Brad Campbell <brad@fnarfbargle.com>

Index: linux-stable/drivers/hwmon/applesmc.c
===================================================================
--- linux-stable.orig/drivers/hwmon/applesmc.c
+++ linux-stable/drivers/hwmon/applesmc.c
@@ -176,7 +176,7 @@ static int wait_status(u8 val, u8 mask)

/* send_byte - Write to SMC data port. Callers must hold applesmc_lock. */

-static int send_byte(u8 cmd, u16 port)
+static int send_byte(u8 cmd)
{
int status;

@@ -186,7 +186,7 @@ static int send_byte(u8 cmd, u16 port)
status = wait_status(SMC_STATUS_BUSY, SMC_STATUS_BUSY);
if (status)
return status;
- outb(cmd, port);
+ outb(cmd, APPLESMC_DATA_PORT);
return 0;
}

@@ -219,10 +219,7 @@ static int smc_sane(void)
ret = send_command(APPLESMC_READ_CMD);
if (ret)
return ret;
- ret = wait_status(0, SMC_STATUS_BUSY);
- if (!ret)
- return ret;
- return -EIO;
+ return wait_status(0, SMC_STATUS_BUSY);
}

static int send_argument(const char *key)
@@ -230,7 +227,7 @@ static int send_argument(const char *key
int i;

for (i = 0; i < 4; i++)
- if (send_byte(key[i], APPLESMC_DATA_PORT))
+ if (send_byte(key[i]))
return -EIO;
return 0;
}
@@ -245,23 +242,14 @@ static int read_smc(u8 cmd, const char *
if (ret)
return ret;

- if (send_command(cmd) || send_argument(key)) {
- pr_warn("%.4s: read arg fail\n", key);
- return -EIO;
- }
-
- /* This has no effect on newer (2012) SMCs */
- if (send_byte(len, APPLESMC_DATA_PORT)) {
- pr_warn("%.4s: read len fail\n", key);
- return -EIO;
- }
+ if (send_command(cmd) || send_argument(key) || send_byte(len))
+ goto err;

for (i = 0; i < len; i++) {
if (wait_status(SMC_STATUS_AWAITING_DATA | SMC_STATUS_BUSY,
- SMC_STATUS_AWAITING_DATA | SMC_STATUS_BUSY) < 0) {
- pr_warn("%.4s: read data[%d] fail\n", key, i);
- return -EIO;
- }
+ SMC_STATUS_AWAITING_DATA | SMC_STATUS_BUSY))
+ goto err;
+
buffer[i] = inb(APPLESMC_DATA_PORT);
}

@@ -277,6 +265,9 @@ static int read_smc(u8 cmd, const char *
pr_warn("flushed %d bytes, last value is: %d\n", i, data);

return wait_status(0, SMC_STATUS_BUSY);
+err:
+ pr_warn("read cmd fail: %x %.4s %d\n", cmd, key, len);
+ return -EIO;
}

static int write_smc(u8 cmd, const char *key, const u8 *buffer, u8 len)
@@ -288,24 +279,17 @@ static int write_smc(u8 cmd, const char
if (ret)
return ret;

- if (send_command(cmd) || send_argument(key)) {
- pr_warn("%s: write arg fail\n", key);
- return -EIO;
- }
+ if (send_command(cmd) || send_argument(key) || send_byte(len))
+ goto err;

- if (send_byte(len, APPLESMC_DATA_PORT)) {
- pr_warn("%.4s: write len fail\n", key);
- return -EIO;
- }
-
- for (i = 0; i < len; i++) {
- if (send_byte(buffer[i], APPLESMC_DATA_PORT)) {
- pr_warn("%s: write data fail\n", key);
- return -EIO;
- }
- }
+ for (i = 0; i < len; i++)
+ if (send_byte(buffer[i]))
+ goto err;

return wait_status(0, SMC_STATUS_BUSY);
+err:
+ pr_warn("write cmd fail: %x %.4s %d\n", cmd, key, len);
+ return -EIO;
}

static int read_register_count(unsigned int *count)