[Skiboot] [PATCH] hdata/i2c: Workaround broken i2c devices
Oliver O'Halloran
oohall at gmail.com
Wed Apr 12 17:14:10 AEST 2017
Some older revisions of hostboot populate the host i2c device fields
with all zero entires. Detect and ignore these so we don't crash on
boot.
Signed-off-by: Oliver O'Halloran <oohall at gmail.com>
---
hdata/i2c.c | 24 +++++++++++++++++++++++-
1 file changed, 23 insertions(+), 1 deletion(-)
diff --git a/hdata/i2c.c b/hdata/i2c.c
index 127068fafdeb..17f9ff1f8edf 100644
--- a/hdata/i2c.c
+++ b/hdata/i2c.c
@@ -132,6 +132,18 @@ static const char *map_label(uint32_t type)
return NULL;
}
+static bool is_zeros(const void *p, size_t size)
+{
+ const char *c = p;
+ size_t i;
+
+ for (i = 0; i < size; i++)
+ if (c[i] != 0)
+ break;
+
+ return i == size;
+}
+
int parse_i2c_devs(const struct HDIF_common_hdr *hdr, int idata_index,
struct dt_node *xscom)
{
@@ -140,6 +152,7 @@ int parse_i2c_devs(const struct HDIF_common_hdr *hdr, int idata_index,
const struct i2c_dev *dev;
const char *label, *name, *compat;
uint32_t i2c_addr;
+ uint32_t size;
int i, count;
/*
@@ -150,7 +163,16 @@ int parse_i2c_devs(const struct HDIF_common_hdr *hdr, int idata_index,
count = HDIF_get_iarray_size(hdr, idata_index);
for (i = 0; i < count; i++) {
- dev = HDIF_get_iarray_item(hdr, idata_index, i, NULL);
+ dev = HDIF_get_iarray_item(hdr, idata_index, i, &size);
+
+ /*
+ * XXX: Some broken hostboots populate i2c devs with zeros.
+ * Workaround them for now.
+ */
+ if (is_zeros(dev, size)) {
+ prerror("I2C: Ignoring broken i2c dev %d\n", i);
+ continue;
+ }
i2cm = get_i2cm_node(xscom, dev->i2cm_engine);
bus = get_bus_node(i2cm, dev->i2cm_port,
--
2.9.3
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