[Linux-stable-mirror] [PATCH 1/3] drm/i915: Pass the correct msgs to gmbus_is_index_read()
From: Ville Syrjälä ville.syrjala@linux.intel.com
We're supposed to examine msgs[i] and msgs[i+1] to see if they form a pair suitable for an indexed transfer. But in reality we're examining msgs[0] and msgs[1]. Fix this.
Cc: stable@vger.kernel.org Cc: Daniel Kurtz djkurtz@chromium.org Cc: Chris Wilson chris@chris-wilson.co.uk Cc: Daniel Vetter daniel.vetter@ffwll.ch Cc: Sean Paul seanpaul@chromium.org Fixes: 56f9eac05489 ("drm/i915/intel_i2c: use INDEX cycles for i2c read transactions") Signed-off-by: Ville Syrjälä ville.syrjala@linux.intel.com --- drivers/gpu/drm/i915/intel_i2c.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/i915/intel_i2c.c b/drivers/gpu/drm/i915/intel_i2c.c index eb5827110d8f..165375cbef2f 100644 --- a/drivers/gpu/drm/i915/intel_i2c.c +++ b/drivers/gpu/drm/i915/intel_i2c.c @@ -484,7 +484,7 @@ do_gmbus_xfer(struct i2c_adapter *adapter, struct i2c_msg *msgs, int num)
for (; i < num; i += inc) { inc = 1; - if (gmbus_is_index_read(msgs, i, num)) { + if (gmbus_is_index_read(&msgs[i], i, num)) { ret = gmbus_xfer_index_read(dev_priv, &msgs[i]); inc = 2; /* an index read is two msgs */ } else if (msgs[i].flags & I2C_M_RD) {
From: Ville Syrjälä ville.syrjala@linux.intel.com
We can only specify the one slave address to indexed reads/writes. Make sure the messages we check are destined to the same slave address before deciding to do an indexed transfer.
Cc: stable@vger.kernel.org Cc: Daniel Kurtz djkurtz@chromium.org Cc: Chris Wilson chris@chris-wilson.co.uk Cc: Daniel Vetter daniel.vetter@ffwll.ch Cc: Sean Paul seanpaul@chromium.org Fixes: 56f9eac05489 ("drm/i915/intel_i2c: use INDEX cycles for i2c read transactions") Signed-off-by: Ville Syrjälä ville.syrjala@linux.intel.com --- drivers/gpu/drm/i915/intel_i2c.c | 1 + 1 file changed, 1 insertion(+)
diff --git a/drivers/gpu/drm/i915/intel_i2c.c b/drivers/gpu/drm/i915/intel_i2c.c index 165375cbef2f..4b4528d7010f 100644 --- a/drivers/gpu/drm/i915/intel_i2c.c +++ b/drivers/gpu/drm/i915/intel_i2c.c @@ -438,6 +438,7 @@ static bool gmbus_is_index_read(struct i2c_msg *msgs, int i, int num) { return (i + 1 < num && + msgs[i].addr == msgs[i + 1].addr && !(msgs[i].flags & I2C_M_RD) && msgs[i].len <= 2 && (msgs[i + 1].flags & I2C_M_RD)); }
Quoting Ville Syrjala (2017-11-23 19:41:56)
From: Ville Syrjälä ville.syrjala@linux.intel.com
We can only specify the one slave address to indexed reads/writes. Make sure the messages we check are destined to the same slave address before deciding to do an indexed transfer.
Cc: stable@vger.kernel.org Cc: Daniel Kurtz djkurtz@chromium.org Cc: Chris Wilson chris@chris-wilson.co.uk Cc: Daniel Vetter daniel.vetter@ffwll.ch Cc: Sean Paul seanpaul@chromium.org Fixes: 56f9eac05489 ("drm/i915/intel_i2c: use INDEX cycles for i2c read transactions") Signed-off-by: Ville Syrjälä ville.syrjala@linux.intel.com
Reviewed-by: Chris Wilson chris@chris-wilson.co.uk -Chris
From: Ville Syrjälä ville.syrjala@linux.intel.com
The hardware always writes one or two bytes in the index portion of an indexed transfer. Make sure the message we send as the index doesn't have a zero length.
Cc: stable@vger.kernel.org Cc: Daniel Kurtz djkurtz@chromium.org Cc: Chris Wilson chris@chris-wilson.co.uk Cc: Daniel Vetter daniel.vetter@ffwll.ch Cc: Sean Paul seanpaul@chromium.org Fixes: 56f9eac05489 ("drm/i915/intel_i2c: use INDEX cycles for i2c read transactions") Signed-off-by: Ville Syrjälä ville.syrjala@linux.intel.com --- drivers/gpu/drm/i915/intel_i2c.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/i915/intel_i2c.c b/drivers/gpu/drm/i915/intel_i2c.c index 4b4528d7010f..8c6b26b5c3fb 100644 --- a/drivers/gpu/drm/i915/intel_i2c.c +++ b/drivers/gpu/drm/i915/intel_i2c.c @@ -439,7 +439,8 @@ gmbus_is_index_read(struct i2c_msg *msgs, int i, int num) { return (i + 1 < num && msgs[i].addr == msgs[i + 1].addr && - !(msgs[i].flags & I2C_M_RD) && msgs[i].len <= 2 && + !(msgs[i].flags & I2C_M_RD) && + (msgs[i].len == 1 || msgs[i].len == 2) && (msgs[i + 1].flags & I2C_M_RD)); }
Quoting Ville Syrjala (2017-11-23 19:41:57)
From: Ville Syrjälä ville.syrjala@linux.intel.com
The hardware always writes one or two bytes in the index portion of an indexed transfer. Make sure the message we send as the index doesn't have a zero length.
Cc: stable@vger.kernel.org Cc: Daniel Kurtz djkurtz@chromium.org Cc: Chris Wilson chris@chris-wilson.co.uk Cc: Daniel Vetter daniel.vetter@ffwll.ch Cc: Sean Paul seanpaul@chromium.org Fixes: 56f9eac05489 ("drm/i915/intel_i2c: use INDEX cycles for i2c read transactions") Signed-off-by: Ville Syrjälä ville.syrjala@linux.intel.com
Reviewed-by: Chris Wilson chris@chris-wilson.co.uk -Chris
Quoting Ville Syrjala (2017-11-23 19:41:55)
From: Ville Syrjälä ville.syrjala@linux.intel.com
We're supposed to examine msgs[i] and msgs[i+1] to see if they form a pair suitable for an indexed transfer. But in reality we're examining msgs[0] and msgs[1]. Fix this.
Cc: stable@vger.kernel.org Cc: Daniel Kurtz djkurtz@chromium.org Cc: Chris Wilson chris@chris-wilson.co.uk Cc: Daniel Vetter daniel.vetter@ffwll.ch Cc: Sean Paul seanpaul@chromium.org Fixes: 56f9eac05489 ("drm/i915/intel_i2c: use INDEX cycles for i2c read transactions") Signed-off-by: Ville Syrjälä ville.syrjala@linux.intel.com
drivers/gpu/drm/i915/intel_i2c.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/i915/intel_i2c.c b/drivers/gpu/drm/i915/intel_i2c.c index eb5827110d8f..165375cbef2f 100644 --- a/drivers/gpu/drm/i915/intel_i2c.c +++ b/drivers/gpu/drm/i915/intel_i2c.c @@ -484,7 +484,7 @@ do_gmbus_xfer(struct i2c_adapter *adapter, struct i2c_msg *msgs, int num) for (; i < num; i += inc) { inc = 1;
if (gmbus_is_index_read(msgs, i, num)) {
if (gmbus_is_index_read(&msgs[i], i, num)) {
i is passed to gmbus_is_index_read() and used as an index into msgs. So this should be accounted for right? -Chris
On Thu, Nov 23, 2017 at 08:50:41PM +0000, Chris Wilson wrote:
Quoting Ville Syrjala (2017-11-23 19:41:55)
From: Ville Syrjälä ville.syrjala@linux.intel.com
We're supposed to examine msgs[i] and msgs[i+1] to see if they form a pair suitable for an indexed transfer. But in reality we're examining msgs[0] and msgs[1]. Fix this.
Cc: stable@vger.kernel.org Cc: Daniel Kurtz djkurtz@chromium.org Cc: Chris Wilson chris@chris-wilson.co.uk Cc: Daniel Vetter daniel.vetter@ffwll.ch Cc: Sean Paul seanpaul@chromium.org Fixes: 56f9eac05489 ("drm/i915/intel_i2c: use INDEX cycles for i2c read transactions") Signed-off-by: Ville Syrjälä ville.syrjala@linux.intel.com
drivers/gpu/drm/i915/intel_i2c.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/i915/intel_i2c.c b/drivers/gpu/drm/i915/intel_i2c.c index eb5827110d8f..165375cbef2f 100644 --- a/drivers/gpu/drm/i915/intel_i2c.c +++ b/drivers/gpu/drm/i915/intel_i2c.c @@ -484,7 +484,7 @@ do_gmbus_xfer(struct i2c_adapter *adapter, struct i2c_msg *msgs, int num) for (; i < num; i += inc) { inc = 1;
if (gmbus_is_index_read(msgs, i, num)) {
if (gmbus_is_index_read(&msgs[i], i, num)) {i is passed to gmbus_is_index_read() and used as an index into msgs. So this should be accounted for right?
Doh. Yep, this patch is nonsense.
On Fri, Nov 24, 2017 at 02:55:28PM +0200, Ville Syrjälä wrote:
On Thu, Nov 23, 2017 at 08:50:41PM +0000, Chris Wilson wrote:
Quoting Ville Syrjala (2017-11-23 19:41:55)
From: Ville Syrjälä ville.syrjala@linux.intel.com
We're supposed to examine msgs[i] and msgs[i+1] to see if they form a pair suitable for an indexed transfer. But in reality we're examining msgs[0] and msgs[1]. Fix this.
Cc: stable@vger.kernel.org Cc: Daniel Kurtz djkurtz@chromium.org Cc: Chris Wilson chris@chris-wilson.co.uk Cc: Daniel Vetter daniel.vetter@ffwll.ch Cc: Sean Paul seanpaul@chromium.org Fixes: 56f9eac05489 ("drm/i915/intel_i2c: use INDEX cycles for i2c read transactions") Signed-off-by: Ville Syrjälä ville.syrjala@linux.intel.com
drivers/gpu/drm/i915/intel_i2c.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/i915/intel_i2c.c b/drivers/gpu/drm/i915/intel_i2c.c index eb5827110d8f..165375cbef2f 100644 --- a/drivers/gpu/drm/i915/intel_i2c.c +++ b/drivers/gpu/drm/i915/intel_i2c.c @@ -484,7 +484,7 @@ do_gmbus_xfer(struct i2c_adapter *adapter, struct i2c_msg *msgs, int num) for (; i < num; i += inc) { inc = 1;
if (gmbus_is_index_read(msgs, i, num)) {
if (gmbus_is_index_read(&msgs[i], i, num)) {i is passed to gmbus_is_index_read() and used as an index into msgs. So this should be accounted for right?
Doh. Yep, this patch is nonsense.
The two other patches pushed to dinq. Thanks catching my mistake with this one.
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