linux-kernel - Re: [PATCH] i2c: mpc: Report correct I2C error codes on Freescale MPC i2c bus driver

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Date:	Wed, 12 Nov 2014 05:08:09 -0800
From:	Danielle Costantino <danielle.costantino@...il.com>
To:	Wolfram Sang <wsa@...-dreams.de>
Cc:	linux-i2c <linux-i2c@...r.kernel.org>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH] i2c: mpc: Report correct I2C error codes on Freescale MPC
 i2c bus driver

From: Danielle Costantino <danielle.costantino@...il.com>
Subject: [PATCH v2] i2c: mpc: report correct I2C error return codes

This patch enforces correct I2C error returned codes from Freescale's
MPC i2c bus driver, allowing for proper user-space/kernel error
handling.

Signed-off-by: Danielle Costantino <danielle.costantino@...il.com>

diff --git a/drivers/i2c/busses/i2c-mpc.c b/drivers/i2c/busses/i2c-mpc.c
index 0edf630..4c5d7d9 100644
--- a/drivers/i2c/busses/i2c-mpc.c
+++ b/drivers/i2c/busses/i2c-mpc.c
@@ -124,7 +124,7 @@
 static int i2c_wait(struct mpc_i2c *i2c, unsigned timeout, int writing)
 {
  unsigned long orig_jiffies = jiffies;
- u32 x;
+ u32 cmd_err;
  int result = 0;

  if (!i2c->irq) {
@@ -133,11 +133,11 @@
  if (time_after(jiffies, orig_jiffies + timeout)) {
  dev_dbg(i2c->dev, "timeout\n");
  writeccr(i2c, 0);
- result = -EIO;
+ result = -ETIMEDOUT;
  break;
  }
  }
- x = readb(i2c->base + MPC_I2C_SR);
+ cmd_err = readb(i2c->base + MPC_I2C_SR);
  writeb(0, i2c->base + MPC_I2C_SR);
  } else {
  /* Interrupt mode */
@@ -150,28 +150,28 @@
  result = -ETIMEDOUT;
  }

- x = i2c->interrupt;
+ cmd_err = i2c->interrupt;
  i2c->interrupt = 0;
  }

  if (result < 0)
  return result;

- if (!(x & CSR_MCF)) {
+ if (!(cmd_err & CSR_MCF)) {
  dev_dbg(i2c->dev, "unfinished\n");
  return -EIO;
  }

- if (x & CSR_MAL) {
+ if (cmd_err & CSR_MAL) {
  dev_dbg(i2c->dev, "MAL\n");
- return -EIO;
+ return -EAGAIN;
  }

- if (writing && (x & CSR_RXAK)) {
+ if (writing && (cmd_err & CSR_RXAK)) {
  dev_dbg(i2c->dev, "No RXAK\n");
  /* generate stop */
  writeccr(i2c, CCR_MEN);
- return -EIO;
+ return -ENXIO;
  }
  return 0;
 }

On Mon, Nov 10, 2014 at 6:49 AM, Wolfram Sang <wsa@...-dreams.de> wrote:
> On Tue, Oct 21, 2014 at 12:05:44AM -0700, Danielle Costantino wrote:
>> From: Danielle Costantino <danielle.costantino@...il.com>
>>
>> This patch enforces correct I2C error returned codes from Freescale's
>> MPC i2c bus driver, allowing for proper user-space/kernel error
>> handling.
>>
>> Signed-off-by: Danielle Costantino <danielle.costantino@...il.com>
>
> Tabs converted to spaces here? Please resend properly.
>



-- 
- Danielle Costantino

View attachment "i2c-mpc-report-correct-I2C-error-return-codes.patch" of type "text/x-patch" (1694 bytes)