Re: [PATCH 44/53] Input: atmel_mxt_ts - Verify Information Block checksum on probe
Yufeng Shen wrote: >> + dev_info(&client->dev, >> +"Family: %u Variant: %u Firmware V%u.%u.%02X Objects: %u\n", >> +info->family_id, info->variant_id, info->version >> 4, >> +info->version & 0xf, info->build, info->object_num); >> + > > Use data->info->XXX here, info was pointing to buf which could have > changed after krealloc. Thank you, that's a really good spot. Caused when I merged the dev_info line into that function. It actually explains a report I had about getting junk in this output but the info_crc check succeeding, hadn't had time to investigate yet. I will fix. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH 44/53] Input: atmel_mxt_ts - Verify Information Block checksum on probe
On Wed, Jun 5, 2013 at 1:37 PM, Nick Dyer wrote:
> By reading the information block and the object table into a contiguous region
> of memory, we can verify the checksum at probe time. This means we verify that
> we are indeed talking to a chip that supports object protocol correctly. We
> also detect I2C comms problems much earlier, resulting in easier diagnosis.
>
> Signed-off-by: Nick Dyer
> Acked-by: Benson Leung
> ---
> drivers/input/touchscreen/atmel_mxt_ts.c | 181
> ++
> 1 file changed, 111 insertions(+), 70 deletions(-)
>
> diff --git a/drivers/input/touchscreen/atmel_mxt_ts.c
> b/drivers/input/touchscreen/atmel_mxt_ts.c
> index bbfea7a..e0ff017 100644
> --- a/drivers/input/touchscreen/atmel_mxt_ts.c
> +++ b/drivers/input/touchscreen/atmel_mxt_ts.c
> @@ -194,7 +194,8 @@ struct mxt_data {
> char phys[64]; /* device physical location */
> struct mxt_platform_data *pdata;
> struct mxt_object *object_table;
> - struct mxt_info info;
> + struct mxt_info *info;
> + void *raw_info_block;
> unsigned int irq;
> unsigned int max_x;
> unsigned int max_y;
> @@ -365,12 +366,16 @@ static int mxt_lookup_bootloader_address(struct
> mxt_data *data, bool retry)
> {
> u8 appmode = data->client->addr;
> u8 bootloader;
> + u8 family_id = 0;
> +
> + if (data->info)
> + family_id = data->info->family_id;
>
> switch (appmode) {
> case 0x4a:
> case 0x4b:
> /* Chips after 1664S use different scheme */
> - if (retry || data->info.family_id >= 0xa2) {
> + if (retry || family_id >= 0xa2) {
> bootloader = appmode - 0x24;
> break;
> }
> @@ -610,7 +615,7 @@ mxt_get_object(struct mxt_data *data, u8 type)
> struct mxt_object *object;
> int i;
>
> - for (i = 0; i < data->info.object_num; i++) {
> + for (i = 0; i < data->info->object_num; i++) {
> object = data->object_table + i;
> if (object->type == type)
> return object;
> @@ -1249,13 +1254,13 @@ static int mxt_check_reg_init(struct mxt_data *data)
> data_pos += offset;
> }
>
> - if (cfg_info.family_id != data->info.family_id) {
> + if (cfg_info.family_id != data->info->family_id) {
> dev_err(dev, "Family ID mismatch!\n");
> ret = -EINVAL;
> goto release;
> }
>
> - if (cfg_info.variant_id != data->info.variant_id) {
> + if (cfg_info.variant_id != data->info->variant_id) {
> dev_err(dev, "Variant ID mismatch!\n");
> ret = -EINVAL;
> goto release;
> @@ -1302,7 +1307,7 @@ static int mxt_check_reg_init(struct mxt_data *data)
>
> /* Malloc memory to store configuration */
> cfg_start_ofs = MXT_OBJECT_START
> - + data->info.object_num * sizeof(struct mxt_object)
> + + data->info->object_num * sizeof(struct mxt_object)
> + MXT_INFO_CHECKSUM_SIZE;
> config_mem_size = data->mem_size - cfg_start_ofs;
> config_mem = kzalloc(config_mem_size, GFP_KERNEL);
> @@ -1510,24 +1515,12 @@ static int mxt_acquire_irq(struct mxt_data *data)
> return 0;
> }
>
> -static int mxt_get_info(struct mxt_data *data)
> -{
> - struct i2c_client *client = data->client;
> - struct mxt_info *info = &data->info;
> - int error;
> -
> - /* Read 7-byte info block starting at address 0 */
> - error = __mxt_read_reg(client, 0, sizeof(*info), info);
> - if (error)
> - return error;
> -
> - return 0;
> -}
> -
> static void mxt_free_object_table(struct mxt_data *data)
> {
> - kfree(data->object_table);
> + kfree(data->raw_info_block);
> data->object_table = NULL;
> + data->info = NULL;
> + data->raw_info_block = NULL;
> kfree(data->msg_buf);
> data->msg_buf = NULL;
> data->enable_reporting = false;
> @@ -1549,25 +1542,17 @@ static void mxt_free_object_table(struct mxt_data
> *data)
> data->max_reportid = 0;
> }
>
> -static int mxt_get_object_table(struct mxt_data *data)
> +static int mxt_parse_object_table(struct mxt_data *data)
> {
> struct i2c_client *client = data->client;
> - size_t table_size;
> - int error;
> int i;
> u8 reportid;
> u16 end_address;
>
> - table_size = data->info.object_num * sizeof(struct mxt_object);
> - error = __mxt_read_reg(client, MXT_OBJECT_START, table_size,
> - data->object_table);
> - if (error)
> - return error;
> -
> /* Valid Report IDs start counting from 1 */
> reportid = 1;
> data->mem_size = 0;
> - for (i = 0; i < data->info.object_num; i++) {
>
[PATCH 44/53] Input: atmel_mxt_ts - Verify Information Block checksum on probe
By reading the information block and the object table into a contiguous region
of memory, we can verify the checksum at probe time. This means we verify that
we are indeed talking to a chip that supports object protocol correctly. We
also detect I2C comms problems much earlier, resulting in easier diagnosis.
Signed-off-by: Nick Dyer
Acked-by: Benson Leung
---
drivers/input/touchscreen/atmel_mxt_ts.c | 181 ++
1 file changed, 111 insertions(+), 70 deletions(-)
diff --git a/drivers/input/touchscreen/atmel_mxt_ts.c
b/drivers/input/touchscreen/atmel_mxt_ts.c
index bbfea7a..e0ff017 100644
--- a/drivers/input/touchscreen/atmel_mxt_ts.c
+++ b/drivers/input/touchscreen/atmel_mxt_ts.c
@@ -194,7 +194,8 @@ struct mxt_data {
char phys[64]; /* device physical location */
struct mxt_platform_data *pdata;
struct mxt_object *object_table;
- struct mxt_info info;
+ struct mxt_info *info;
+ void *raw_info_block;
unsigned int irq;
unsigned int max_x;
unsigned int max_y;
@@ -365,12 +366,16 @@ static int mxt_lookup_bootloader_address(struct mxt_data
*data, bool retry)
{
u8 appmode = data->client->addr;
u8 bootloader;
+ u8 family_id = 0;
+
+ if (data->info)
+ family_id = data->info->family_id;
switch (appmode) {
case 0x4a:
case 0x4b:
/* Chips after 1664S use different scheme */
- if (retry || data->info.family_id >= 0xa2) {
+ if (retry || family_id >= 0xa2) {
bootloader = appmode - 0x24;
break;
}
@@ -610,7 +615,7 @@ mxt_get_object(struct mxt_data *data, u8 type)
struct mxt_object *object;
int i;
- for (i = 0; i < data->info.object_num; i++) {
+ for (i = 0; i < data->info->object_num; i++) {
object = data->object_table + i;
if (object->type == type)
return object;
@@ -1249,13 +1254,13 @@ static int mxt_check_reg_init(struct mxt_data *data)
data_pos += offset;
}
- if (cfg_info.family_id != data->info.family_id) {
+ if (cfg_info.family_id != data->info->family_id) {
dev_err(dev, "Family ID mismatch!\n");
ret = -EINVAL;
goto release;
}
- if (cfg_info.variant_id != data->info.variant_id) {
+ if (cfg_info.variant_id != data->info->variant_id) {
dev_err(dev, "Variant ID mismatch!\n");
ret = -EINVAL;
goto release;
@@ -1302,7 +1307,7 @@ static int mxt_check_reg_init(struct mxt_data *data)
/* Malloc memory to store configuration */
cfg_start_ofs = MXT_OBJECT_START
- + data->info.object_num * sizeof(struct mxt_object)
+ + data->info->object_num * sizeof(struct mxt_object)
+ MXT_INFO_CHECKSUM_SIZE;
config_mem_size = data->mem_size - cfg_start_ofs;
config_mem = kzalloc(config_mem_size, GFP_KERNEL);
@@ -1510,24 +1515,12 @@ static int mxt_acquire_irq(struct mxt_data *data)
return 0;
}
-static int mxt_get_info(struct mxt_data *data)
-{
- struct i2c_client *client = data->client;
- struct mxt_info *info = &data->info;
- int error;
-
- /* Read 7-byte info block starting at address 0 */
- error = __mxt_read_reg(client, 0, sizeof(*info), info);
- if (error)
- return error;
-
- return 0;
-}
-
static void mxt_free_object_table(struct mxt_data *data)
{
- kfree(data->object_table);
+ kfree(data->raw_info_block);
data->object_table = NULL;
+ data->info = NULL;
+ data->raw_info_block = NULL;
kfree(data->msg_buf);
data->msg_buf = NULL;
data->enable_reporting = false;
@@ -1549,25 +1542,17 @@ static void mxt_free_object_table(struct mxt_data *data)
data->max_reportid = 0;
}
-static int mxt_get_object_table(struct mxt_data *data)
+static int mxt_parse_object_table(struct mxt_data *data)
{
struct i2c_client *client = data->client;
- size_t table_size;
- int error;
int i;
u8 reportid;
u16 end_address;
- table_size = data->info.object_num * sizeof(struct mxt_object);
- error = __mxt_read_reg(client, MXT_OBJECT_START, table_size,
- data->object_table);
- if (error)
- return error;
-
/* Valid Report IDs start counting from 1 */
reportid = 1;
data->mem_size = 0;
- for (i = 0; i < data->info.object_num; i++) {
+ for (i = 0; i < data->info->object_num; i++) {
struct mxt_object *object = data->object_table + i;
u8 min_id, max_id;
@@ -1591,7 +1576,7 @@ static int mxt_get_object_table(struct mxt_data *data)
switch (object->type) {
case M
