From ffd3d3361d583cb73fa65a5fed3a196ba6f261bb Mon Sep 17 00:00:00 2001 From: Alex Deucher Date: Tue, 3 Dec 2013 17:16:49 -0500 Subject: [PATCH] drm/radeon/atom: fix bus probes when hw_i2c is set (v2) When probing the bus, we need to set the byte count to 0 rather than 1. v2: Don't count the first byte. bug: https://bugzilla.kernel.org/show_bug.cgi?id=66241 Signed-off-by: Alex Deucher Cc: stable@vger.kernel.org --- drivers/gpu/drm/radeon/atombios_i2c.c | 15 +++++++++------ 1 file changed, 9 insertions(+), 6 deletions(-) diff --git a/drivers/gpu/drm/radeon/atombios_i2c.c b/drivers/gpu/drm/radeon/atombios_i2c.c index 0652ee0a2098..f685035dbe39 100644 --- a/drivers/gpu/drm/radeon/atombios_i2c.c +++ b/drivers/gpu/drm/radeon/atombios_i2c.c @@ -44,7 +44,7 @@ static int radeon_process_i2c_ch(struct radeon_i2c_chan *chan, PROCESS_I2C_CHANNEL_TRANSACTION_PS_ALLOCATION args; int index = GetIndexIntoMasterTable(COMMAND, ProcessI2cChannelTransaction); unsigned char *base; - u16 out; + u16 out = cpu_to_le16(0); memset(&args, 0, sizeof(args)); @@ -55,11 +55,14 @@ static int radeon_process_i2c_ch(struct radeon_i2c_chan *chan, DRM_ERROR("hw i2c: tried to write too many bytes (%d vs 3)\n", num); return -EINVAL; } - args.ucRegIndex = buf[0]; - if (num > 1) { + if (buf == NULL) + args.ucRegIndex = 0; + else + args.ucRegIndex = buf[0]; + if (num) num--; + if (num) memcpy(&out, &buf[1], num); - } args.lpI2CDataOut = cpu_to_le16(out); } else { if (num > ATOM_MAX_HW_I2C_READ) { @@ -96,14 +99,14 @@ int radeon_atom_hw_i2c_xfer(struct i2c_adapter *i2c_adap, struct radeon_i2c_chan *i2c = i2c_get_adapdata(i2c_adap); struct i2c_msg *p; int i, remaining, current_count, buffer_offset, max_bytes, ret; - u8 buf = 0, flags; + u8 flags; /* check for bus probe */ p = &msgs[0]; if ((num == 1) && (p->len == 0)) { ret = radeon_process_i2c_ch(i2c, p->addr, HW_I2C_WRITE, - &buf, 1); + NULL, 0); if (ret) return ret; else -- 2.39.5