Update to optoe driver to improve EOF handling (#44)

Added patch: 'driver-support-optoe-EOF_fix.patch' to patch directory
	Added the patch to 'series

Signed-off-by: Don Bollinger

patch/driver-support-optoe-EOF_fix.patch

@@ -0,0 +1,149 @@
+From 556c452dcf5706a951ef490327b74bd27a411693 Mon Sep 17 00:00:00 2001
+From: Don Bollinger <don@thebollingers.org>
+Date: Fri, 9 Mar 2018 18:22:33 -0800
+Subject: [PATCH] drivers/misc/eeprom:  Improve EOF handling
+
+   Change -ENXIO error to return zero, which user space sees as EOF
+   Detect SFP devices with only one I2C address (DAC devices)
+   Correctly handle partial read, returning actual bytes transferred
+
+Signed-off-by: Don Bollinger
+---
+ drivers/misc/eeprom/optoe.c | 52 +++++++++++++++++++++++++++++++--------------
+ 1 file changed, 36 insertions(+), 16 deletions(-)
+
+diff --git a/drivers/misc/eeprom/optoe.c b/drivers/misc/eeprom/optoe.c
+index 7425bf6..b3064f0 100644
+--- a/drivers/misc/eeprom/optoe.c
++++ b/drivers/misc/eeprom/optoe.c
+@@ -158,6 +158,7 @@ struct optoe_platform_data {
+  */
+ #define TWO_ADDR_EEPROM_SIZE ((3 + OPTOE_ARCH_PAGES) * OPTOE_PAGE_SIZE)
+ #define TWO_ADDR_EEPROM_UNPAGED_SIZE (4 * OPTOE_PAGE_SIZE)
++#define TWO_ADDR_NO_0X51_SIZE (2 * OPTOE_PAGE_SIZE)
+
+ /* a few constants to find our way around the EEPROM */
+ #define OPTOE_PAGE_SELECT_REG   0x7F
+@@ -165,9 +166,12 @@ struct optoe_platform_data {
+ #define ONE_ADDR_NOT_PAGEABLE (1<<2)
+ #define TWO_ADDR_PAGEABLE_REG 0x40
+ #define TWO_ADDR_PAGEABLE (1<<4)
++#define TWO_ADDR_0X51_REG 92
++#define TWO_ADDR_0X51_SUPP (1<<6)
+ #define OPTOE_ID_REG 0
+ #define OPTOE_READ_OP 0
+ #define OPTOE_WRITE_OP 1
++#define OPTOE_EOF 0  /* used for access beyond end of device */
+
+ struct optoe_data {
+ 	struct optoe_platform_data chip;
+@@ -564,7 +568,7 @@ static ssize_t optoe_eeprom_update_client(struct optoe_data *optoe,
+  * Returns updated len for this access:
+  *     - entire access is legal, original len is returned.
+  *     - access begins legal but is too long, len is truncated to fit.
+- *     - initial offset exceeds supported pages, return -EINVAL
++ *     - initial offset exceeds supported pages, return OPTOE_EOF (zero)
+  */
+ static ssize_t optoe_page_legal(struct optoe_data *optoe,
+ 		loff_t off, size_t len)
+@@ -578,12 +582,12 @@ static ssize_t optoe_page_legal(struct optoe_data *optoe,
+ 		return -EINVAL;
+ 	if (optoe->dev_class == TWO_ADDR) {
+ 		/* SFP case */
+-		/* if no pages needed, we're good */
+-		if ((off + len) <= TWO_ADDR_EEPROM_UNPAGED_SIZE)
++		/* if only using addr 0x50 (first 256 bytes) we're good */
++		if ((off + len) <= TWO_ADDR_NO_0X51_SIZE)
+ 			return len;
+ 		/* if offset exceeds possible pages, we're not good */
+ 		if (off >= TWO_ADDR_EEPROM_SIZE)
+-			return -EINVAL;
++			return OPTOE_EOF;
+ 		/* in between, are pages supported? */
+ 		status = optoe_eeprom_read(optoe, client, &regval,
+ 				TWO_ADDR_PAGEABLE_REG, 1);
+@@ -595,8 +599,23 @@ static ssize_t optoe_page_legal(struct optoe_data *optoe,
+ 		} else {
+ 			/* pages not supported, trim len to unpaged size */
+ 			if (off >= TWO_ADDR_EEPROM_UNPAGED_SIZE)
+-				return -EINVAL;
+-			maxlen = TWO_ADDR_EEPROM_UNPAGED_SIZE - off;
++				return OPTOE_EOF;
++
++			/* will be accessing addr 0x51, is that supported? */
++			/* byte 92, bit 6 implies DDM support, 0x51 support */
++			status = optoe_eeprom_read(optoe, client, &regval,
++						TWO_ADDR_0X51_REG, 1);
++			if (status < 0)
++				return status;
++			if (regval & TWO_ADDR_0X51_SUPP) {
++				/* addr 0x51 is OK */
++				maxlen = TWO_ADDR_EEPROM_UNPAGED_SIZE - off;
++			} else {
++				/* addr 0x51 NOT supported, trim to 256 max */
++				if (off >= TWO_ADDR_NO_0X51_SIZE)
++					return OPTOE_EOF;
++				maxlen = TWO_ADDR_NO_0X51_SIZE - off;
++			}
+ 		}
+ 		len = (len > maxlen) ? maxlen : len;
+ 		dev_dbg(&client->dev,
+@@ -609,7 +628,7 @@ static ssize_t optoe_page_legal(struct optoe_data *optoe,
+ 			return len;
+ 		/* if offset exceeds possible pages, we're not good */
+ 		if (off >= ONE_ADDR_EEPROM_SIZE)
+-			return -EINVAL;
++			return OPTOE_EOF;
+ 		/* in between, are pages supported? */
+ 		status = optoe_eeprom_read(optoe, client, &regval,
+ 				ONE_ADDR_PAGEABLE_REG, 1);
+@@ -618,7 +637,7 @@ static ssize_t optoe_page_legal(struct optoe_data *optoe,
+ 		if (regval & ONE_ADDR_NOT_PAGEABLE) {
+ 			/* pages not supported, trim len to unpaged size */
+ 			if (off >= ONE_ADDR_EEPROM_UNPAGED_SIZE)
+-				return -EINVAL;
++				return OPTOE_EOF;
+ 			maxlen = ONE_ADDR_EEPROM_UNPAGED_SIZE - off;
+ 		} else {
+ 			/* Pages supported, trim len to the end of pages */
+@@ -659,8 +678,10 @@ static ssize_t optoe_read_write(struct optoe_data *optoe,
+ 	 * Confirm this access fits within the device suppored addr range
+ 	 */
+ 	status = optoe_page_legal(optoe, off, len);
+-	if (status < 0)
+-		goto err;
++	if ((status == OPTOE_EOF) || (status < 0)) {
++		mutex_unlock(&optoe->lock);
++		return status;
++	}
+ 	len = status;
+
+ 	/*
+@@ -720,7 +741,11 @@ static ssize_t optoe_read_write(struct optoe_data *optoe,
+ 			dev_dbg(&client->dev,
+ 			"o_u_c: chunk %d c_offset %lld c_len %ld failed %d!\n",
+ 			chunk, chunk_offset, (long int) chunk_len, status);
+-			goto err;
++			if (status > 0)
++				retval += status;
++			if (retval == 0)
++				retval = status;
++			break;
+ 		}
+ 		buf += status;
+ 		pending_len -= status;
+@@ -729,11 +754,6 @@ static ssize_t optoe_read_write(struct optoe_data *optoe,
+ 	mutex_unlock(&optoe->lock);
+
+ 	return retval;
+-
+-err:
+-	mutex_unlock(&optoe->lock);
+-
+-	return status;
+ }
+
+ static ssize_t optoe_bin_read(struct file *filp, struct kobject *kobj,
+-- 
+2.11.0
+

patch/series

@@ -33,3 +33,4 @@ driver-support-tun-config-carrier-enable.patch
 driver-i2c-bus-ismt-i801-support-intel-denverton.patch
 driver-hwmon-max31790.patch
 driver-support-optoe.patch
+driver-support-optoe-EOF_fix.patch