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authorEugen Hristev <eugen.hristev@microchip.com>2020-12-04 18:06:55 +0200
committerHeiko Schocher <hs@denx.de>2021-02-21 06:05:08 +0100
commit73c16692bcf7505d01596f48d2006dadfa3d14ab (patch)
treea83532fccdae9b6f9b7d7da1a32afb6f5f78a832 /drivers/i2c
parent6befb51f349459c96ed64412070feda7472cf152 (diff)
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i2c: at91: fix crash when using 'i2c probe'
When issuing 'i2c probe', the driver was crashing, because at probe there is a request with zero length buffer to write to i2c bus. The xfer_msg function assumes the buffer is always there, and never checks for the buffer length. => i2c dev 0 Setting bus to 0 => i2c probe Valid chip addresses: data abort pc : [<7ffa97dc>] lr : [<7ffa96f8>] reloc pc : [<66f277dc>] lr : [<66f276f8>] sp : 7fb7c110 ip : 7ff87a28 fp : 7ff99938 r10: 00000002 r9 : 7fb7dec0 r8 : 00000000 r7 : e181c600 r6 : 7fb88c20 r5 : 00000000 r4 : 7fb7c128 r3 : 00000000 r2 : 00000001 r1 : 00000000 r0 : 00000009 Flags: nZCv IRQs off FIQs off Mode SVC_32 Code: eb0092f4 e1a00005 e8bd81f0 e594300c (e5d33000) Resetting CPU ... Fixes: 8800e0fa20 ("i2c: atmel: add i2c driver") Signed-off-by: Eugen Hristev <eugen.hristev@microchip.com>
Diffstat (limited to 'drivers/i2c')
-rw-r--r--drivers/i2c/at91_i2c.c4
1 files changed, 4 insertions, 0 deletions
diff --git a/drivers/i2c/at91_i2c.c b/drivers/i2c/at91_i2c.c
index aca8de9..6b4c0e4 100644
--- a/drivers/i2c/at91_i2c.c
+++ b/drivers/i2c/at91_i2c.c
@@ -51,6 +51,10 @@ static int at91_i2c_xfer_msg(struct at91_i2c_bus *bus, struct i2c_msg *msg)
u32 i;
int ret = 0;
+ /* if there is no message to send/receive, just exit quietly */
+ if (msg->len == 0)
+ return ret;
+
readl(&reg->sr);
if (is_read) {
writel(TWI_CR_START, &reg->cr);