| Message ID | 20190905144122.5689-1-lee.jones@linaro.org (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | 127068abe85bf3dee50df51cb039a5a987a4a666 |
| Headers | show |
| Series | [RESEND,v3,1/1] i2c: qcom-geni: Provide an option to disable DMA processing | expand |
On Thu, Sep 05, 2019 at 03:41:22PM +0100, Lee Jones wrote: > We have a production-level laptop (Lenovo Yoga C630) which is exhibiting > a rather horrific bug. When I2C HID devices are being scanned for at > boot-time the QCom Geni based I2C (Serial Engine) attempts to use DMA. > When it does, the laptop reboots and the user never sees the OS. $subject is still wrong. And a paragraph that you are/were debugging the root cause but to no avail so DMA gets disabled for now would be good for a hotfix this late in the cycle. > > Signed-off-by: Lee Jones <lee.jones@linaro.org> > --- > drivers/i2c/busses/i2c-qcom-geni.c | 12 ++++++++---- > 1 file changed, 8 insertions(+), 4 deletions(-) > > diff --git a/drivers/i2c/busses/i2c-qcom-geni.c b/drivers/i2c/busses/i2c-qcom-geni.c > index a89bfce5388e..17abf60c94ae 100644 > --- a/drivers/i2c/busses/i2c-qcom-geni.c > +++ b/drivers/i2c/busses/i2c-qcom-geni.c > @@ -355,11 +355,13 @@ static int geni_i2c_rx_one_msg(struct geni_i2c_dev *gi2c, struct i2c_msg *msg, > { > dma_addr_t rx_dma; > unsigned long time_left; > - void *dma_buf; > + void *dma_buf = NULL; > struct geni_se *se = &gi2c->se; > size_t len = msg->len; > > - dma_buf = i2c_get_dma_safe_msg_buf(msg, 32); > + if (!of_machine_is_compatible("lenovo,yoga-c630")) > + dma_buf = i2c_get_dma_safe_msg_buf(msg, 32); > + > if (dma_buf) > geni_se_select_mode(se, GENI_SE_DMA); > else > @@ -394,11 +396,13 @@ static int geni_i2c_tx_one_msg(struct geni_i2c_dev *gi2c, struct i2c_msg *msg, > { > dma_addr_t tx_dma; > unsigned long time_left; > - void *dma_buf; > + void *dma_buf = NULL; > struct geni_se *se = &gi2c->se; > size_t len = msg->len; > > - dma_buf = i2c_get_dma_safe_msg_buf(msg, 32); > + if (!of_machine_is_compatible("lenovo,yoga-c630")) > + dma_buf = i2c_get_dma_safe_msg_buf(msg, 32); > + > if (dma_buf) > geni_se_select_mode(se, GENI_SE_DMA); > else > -- > 2.17.1 >
diff --git a/drivers/i2c/busses/i2c-qcom-geni.c b/drivers/i2c/busses/i2c-qcom-geni.c index a89bfce5388e..17abf60c94ae 100644 --- a/drivers/i2c/busses/i2c-qcom-geni.c +++ b/drivers/i2c/busses/i2c-qcom-geni.c @@ -355,11 +355,13 @@ static int geni_i2c_rx_one_msg(struct geni_i2c_dev *gi2c, struct i2c_msg *msg, { dma_addr_t rx_dma; unsigned long time_left; - void *dma_buf; + void *dma_buf = NULL; struct geni_se *se = &gi2c->se; size_t len = msg->len; - dma_buf = i2c_get_dma_safe_msg_buf(msg, 32); + if (!of_machine_is_compatible("lenovo,yoga-c630")) + dma_buf = i2c_get_dma_safe_msg_buf(msg, 32); + if (dma_buf) geni_se_select_mode(se, GENI_SE_DMA); else @@ -394,11 +396,13 @@ static int geni_i2c_tx_one_msg(struct geni_i2c_dev *gi2c, struct i2c_msg *msg, { dma_addr_t tx_dma; unsigned long time_left; - void *dma_buf; + void *dma_buf = NULL; struct geni_se *se = &gi2c->se; size_t len = msg->len; - dma_buf = i2c_get_dma_safe_msg_buf(msg, 32); + if (!of_machine_is_compatible("lenovo,yoga-c630")) + dma_buf = i2c_get_dma_safe_msg_buf(msg, 32); + if (dma_buf) geni_se_select_mode(se, GENI_SE_DMA); else
We have a production-level laptop (Lenovo Yoga C630) which is exhibiting a rather horrific bug. When I2C HID devices are being scanned for at boot-time the QCom Geni based I2C (Serial Engine) attempts to use DMA. When it does, the laptop reboots and the user never sees the OS. Signed-off-by: Lee Jones <lee.jones@linaro.org> --- drivers/i2c/busses/i2c-qcom-geni.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-)