From: Dan Carpenter <dan.carpenter@linaro.org>
To: dmitry.baryshkov@linaro.org
Cc: linux-usb@vger.kernel.org
Subject: [bug report] usb: typec: ucsi: extract code to read PD caps
Date: Thu, 11 Apr 2024 16:20:22 +0300 [thread overview]
Message-ID: <a3a2799c-04b3-4b8a-b808-5a118b330619@moroto.mountain> (raw)
Hello Dmitry Baryshkov,
Commit ad4bc68bef3e ("usb: typec: ucsi: extract code to read PD
caps") from Mar 29, 2024 (linux-next), leads to the following Smatch
static checker warning:
drivers/usb/typec/ucsi/ucsi.c:689 ucsi_get_pd_caps()
warn: passing zero to 'ERR_PTR'
drivers/usb/typec/ucsi/ucsi.c
680 static struct usb_power_delivery_capabilities *ucsi_get_pd_caps(struct ucsi_connector *con,
681 enum typec_role role,
682 bool is_partner)
683 {
684 struct usb_power_delivery_capabilities_desc pd_caps;
685 int ret;
686
687 ret = ucsi_get_pdos(con, role, is_partner, pd_caps.pdo);
688 if (ret <= 0)
--> 689 return ERR_PTR(ret);
This is returns NULL if ucsi_get_pdos() returns zero. It's really hard
to say if this is intentional or not... Originally, we treated error
codes and zero the same but we didn't report errors back to the user,
the code just continued silently. Now it's reporting errors but just
continuing along if ucsi_get_pdos() returns zero.
My instinct says that we should modify ucsi_get_pdos() to not return
zero but I don't know the code...
diff --git a/drivers/usb/typec/ucsi/ucsi.c b/drivers/usb/typec/ucsi/ucsi.c
index 8abde8db6bcf..427b7610a074 100644
--- a/drivers/usb/typec/ucsi/ucsi.c
+++ b/drivers/usb/typec/ucsi/ucsi.c
@@ -650,6 +650,8 @@ static int ucsi_get_pdos(struct ucsi_connector *con, enum typec_role role,
return ret;
num_pdos = ret / sizeof(u32); /* number of bytes to 32-bit PDOs */
+ if (num_pdos == 0)
+ return -EINVAL;
if (num_pdos < UCSI_MAX_PDOS)
return num_pdos;
Or, if returning NULL is intentional then it would be nice to add a
comment.
690
691 if (ret < PDO_MAX_OBJECTS)
692 pd_caps.pdo[ret] = 0;
693
694 pd_caps.role = role;
695
696 return usb_power_delivery_register_capabilities(is_partner ? con->partner_pd : con->pd,
697 &pd_caps);
698 }
regards,
dan carpenter
next reply other threads:[~2024-04-11 13:20 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-04-11 13:20 Dan Carpenter [this message]
2024-04-11 20:25 ` [bug report] usb: typec: ucsi: extract code to read PD caps Dmitry Baryshkov
2024-04-14 11:52 ` Dan Carpenter
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