Re: [PATCH v2 1/2] usb: typec: ucsi: fix UCSI on buggy Qualcomm devices

[Neil Armstrong <neil.armstrong@linaro.org>]

Hi,

On 25/10/2023 13:49, Dmitry Baryshkov wrote:
> On sevral Qualcomm platforms (SC8180X, SM8350, SC8280XP) a call to

    s/sevral/several/

> UCSI_GET_PDOS for non-PD partners will cause a firmware crash with no
> easy way to recover from it. Since we have no easy way to determine
> whether the partner really has PD support, shortcut UCSI_GET_PDOS on
> such platforms. This allows us to enable UCSI support on such devices.
> 
> Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
> ---
>   drivers/usb/typec/ucsi/ucsi.c       |  3 +++
>   drivers/usb/typec/ucsi/ucsi.h       |  3 +++
>   drivers/usb/typec/ucsi/ucsi_glink.c | 13 +++++++++++++
>   3 files changed, 19 insertions(+)
> 
> diff --git a/drivers/usb/typec/ucsi/ucsi.c b/drivers/usb/typec/ucsi/ucsi.c
> index 61b64558f96c..5392ec698959 100644
> --- a/drivers/usb/typec/ucsi/ucsi.c
> +++ b/drivers/usb/typec/ucsi/ucsi.c
> @@ -578,6 +578,9 @@ static int ucsi_read_pdos(struct ucsi_connector *con,
>   	u64 command;
>   	int ret;
>   
> +	if (ucsi->quirks & UCSI_NO_PARTNER_PDOS)
> +		return 0;
> +
>   	command = UCSI_COMMAND(UCSI_GET_PDOS) | UCSI_CONNECTOR_NUMBER(con->num);
>   	command |= UCSI_GET_PDOS_PARTNER_PDO(is_partner);
>   	command |= UCSI_GET_PDOS_PDO_OFFSET(offset);
> diff --git a/drivers/usb/typec/ucsi/ucsi.h b/drivers/usb/typec/ucsi/ucsi.h
> index 474315a72c77..6478016d5cb8 100644
> --- a/drivers/usb/typec/ucsi/ucsi.h
> +++ b/drivers/usb/typec/ucsi/ucsi.h
> @@ -317,6 +317,9 @@ struct ucsi {
>   #define EVENT_PENDING	0
>   #define COMMAND_PENDING	1
>   #define ACK_PENDING	2
> +
> +	unsigned long quirks;
> +#define UCSI_NO_PARTNER_PDOS	BIT(0)	/* Don't read partner's PDOs */
>   };
>   
>   #define UCSI_MAX_SVID		5
> diff --git a/drivers/usb/typec/ucsi/ucsi_glink.c b/drivers/usb/typec/ucsi/ucsi_glink.c
> index db6e248f8208..a94e2df6fd45 100644
> --- a/drivers/usb/typec/ucsi/ucsi_glink.c
> +++ b/drivers/usb/typec/ucsi/ucsi_glink.c
> @@ -6,6 +6,7 @@
>   #include <linux/auxiliary_bus.h>
>   #include <linux/module.h>
>   #include <linux/mutex.h>
> +#include <linux/of_device.h>
>   #include <linux/property.h>
>   #include <linux/soc/qcom/pdr.h>
>   #include <linux/usb/typec_mux.h>
> @@ -296,11 +297,19 @@ static void pmic_glink_ucsi_destroy(void *data)
>   	mutex_unlock(&ucsi->lock);
>   }
>   
> +static const struct of_device_id pmic_glink_ucsi_of_quirks[] = {
> +	{ .compatible = "qcom,sc8180x-pmic-glink", .data = (void *)UCSI_NO_PARTNER_PDOS, },
> +	{ .compatible = "qcom,sc8280xp-pmic-glink", .data = (void *)UCSI_NO_PARTNER_PDOS, },
> +	{ .compatible = "qcom,sm8350-pmic-glink", .data = (void *)UCSI_NO_PARTNER_PDOS, },
> +	{}
> +};
> +
>   static int pmic_glink_ucsi_probe(struct auxiliary_device *adev,
>   				 const struct auxiliary_device_id *id)
>   {
>   	struct pmic_glink_ucsi *ucsi;
>   	struct device *dev = &adev->dev;
> +	const struct of_device_id *match;
>   	struct fwnode_handle *fwnode;
>   	int ret;
>   
> @@ -327,6 +336,10 @@ static int pmic_glink_ucsi_probe(struct auxiliary_device *adev,
>   	if (ret)
>   		return ret;
>   
> +	match = of_match_device(pmic_glink_ucsi_of_quirks, dev->parent);
> +	if (match)
> +		ucsi->ucsi->quirks = (unsigned long)match->data;
> +
>   	ucsi_set_drvdata(ucsi->ucsi, ucsi);
>   
>   	device_for_each_child_node(dev, fwnode) {

With typo fixed:

Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>