From: Harsh Kumar <harsh1kumar@gmail.com>
To: kernel-janitors@vger.kernel.org
Subject: [Patch 1/2] Staging: winbond: Check for unsuccessful allocation immediately
Date: Fri, 31 May 2013 15:42:42 +0000 [thread overview]
Message-ID: <51A8C222.20806@gmail.com> (raw)
Check to see if allocation by kzalloc() or usb_alloc_urb() was unsuccessful
immediately after the allocation. Exit from the function can be right at that
point in case of allocation failure.
This avoids unnecessary use of usb_alloc_urb() & usb_free_urb() if kzalloc()
returns NULL.
Also, makes the code better structured & easier to understand.
Signed-off-by: Harsh Kumar <harsh1kumar@gmail.com>
---
drivers/staging/winbond/wb35reg.c | 265 +++++++++++++++++++++++++++++++-------------------------------
1 file changed, 136 insertions(+), 129 deletions(-)
diff -uprN a/drivers/staging/winbond/wb35reg.c b/drivers/staging/winbond/wb35reg.c
--- a/drivers/staging/winbond/wb35reg.c 2013-05-31 19:47:16.824056618 +0530
+++ b/drivers/staging/winbond/wb35reg.c 2013-05-31 20:03:17.560035177 +0530
@@ -30,45 +30,46 @@ unsigned char Wb35Reg_BurstWrite(struct
/* Trying to use burst write function if use new hardware */
UrbSize = sizeof(struct wb35_reg_queue) + DataSize + sizeof(struct usb_ctrlrequest);
reg_queue = kzalloc(UrbSize, GFP_ATOMIC);
+ if (reg_queue = NULL)
+ return false;
+
urb = usb_alloc_urb(0, GFP_ATOMIC);
- if (urb && reg_queue) {
- reg_queue->DIRECT = 2; /* burst write register */
- reg_queue->INDEX = RegisterNo;
- reg_queue->pBuffer = (u32 *)((u8 *)reg_queue + sizeof(struct wb35_reg_queue));
- memcpy(reg_queue->pBuffer, pRegisterData, DataSize);
- /* the function for reversing register data from little endian to big endian */
- for (i = 0; i < NumberOfData ; i++)
- reg_queue->pBuffer[i] = cpu_to_le32(reg_queue->pBuffer[i]);
-
- dr = (struct usb_ctrlrequest *)((u8 *)reg_queue + sizeof(struct wb35_reg_queue) + DataSize);
- dr->bRequestType = USB_TYPE_VENDOR | USB_DIR_OUT | USB_RECIP_DEVICE;
- dr->bRequest = 0x04; /* USB or vendor-defined request code, burst mode */
- dr->wValue = cpu_to_le16(Flag); /* 0: Register number auto-increment, 1: No auto increment */
- dr->wIndex = cpu_to_le16(RegisterNo);
- dr->wLength = cpu_to_le16(DataSize);
- reg_queue->Next = NULL;
- reg_queue->pUsbReq = dr;
- reg_queue->urb = urb;
-
- spin_lock_irq(®->EP0VM_spin_lock);
- if (reg->reg_first = NULL)
- reg->reg_first = reg_queue;
- else
- reg->reg_last->Next = reg_queue;
- reg->reg_last = reg_queue;
-
- spin_unlock_irq(®->EP0VM_spin_lock);
-
- /* Start EP0VM */
- Wb35Reg_EP0VM_start(pHwData);
-
- return true;
- } else {
- usb_free_urb(urb);
+ if (urb = NULL) {
kfree(reg_queue);
return false;
}
- return false;
+
+ reg_queue->DIRECT = 2; /* burst write register */
+ reg_queue->INDEX = RegisterNo;
+ reg_queue->pBuffer = (u32 *)((u8 *)reg_queue + sizeof(struct wb35_reg_queue));
+ memcpy(reg_queue->pBuffer, pRegisterData, DataSize);
+ /* the function for reversing register data from little endian to big endian */
+ for (i = 0; i < NumberOfData ; i++)
+ reg_queue->pBuffer[i] = cpu_to_le32(reg_queue->pBuffer[i]);
+
+ dr = (struct usb_ctrlrequest *)((u8 *)reg_queue + sizeof(struct wb35_reg_queue) + DataSize);
+ dr->bRequestType = USB_TYPE_VENDOR | USB_DIR_OUT | USB_RECIP_DEVICE;
+ dr->bRequest = 0x04; /* USB or vendor-defined request code, burst mode */
+ dr->wValue = cpu_to_le16(Flag); /* 0: Register number auto-increment, 1: No auto increment */
+ dr->wIndex = cpu_to_le16(RegisterNo);
+ dr->wLength = cpu_to_le16(DataSize);
+ reg_queue->Next = NULL;
+ reg_queue->pUsbReq = dr;
+ reg_queue->urb = urb;
+
+ spin_lock_irq(®->EP0VM_spin_lock);
+ if (reg->reg_first = NULL)
+ reg->reg_first = reg_queue;
+ else
+ reg->reg_last->Next = reg_queue;
+ reg->reg_last = reg_queue;
+
+ spin_unlock_irq(®->EP0VM_spin_lock);
+
+ /* Start EP0VM */
+ Wb35Reg_EP0VM_start(pHwData);
+
+ return true;
}
void Wb35Reg_Update(struct hw_data *pHwData, u16 RegisterNo, u32 RegisterValue)
@@ -173,42 +174,44 @@ unsigned char Wb35Reg_Write(struct hw_da
/* update the register by send urb request */
UrbSize = sizeof(struct wb35_reg_queue) + sizeof(struct usb_ctrlrequest);
reg_queue = kzalloc(UrbSize, GFP_ATOMIC);
+ if (reg_queue = NULL)
+ return false;
+
urb = usb_alloc_urb(0, GFP_ATOMIC);
- if (urb && reg_queue) {
- reg_queue->DIRECT = 1; /* burst write register */
- reg_queue->INDEX = RegisterNo;
- reg_queue->VALUE = cpu_to_le32(RegisterValue);
- reg_queue->RESERVED_VALID = false;
- dr = (struct usb_ctrlrequest *)((u8 *)reg_queue + sizeof(struct wb35_reg_queue));
- dr->bRequestType = USB_TYPE_VENDOR | USB_DIR_OUT | USB_RECIP_DEVICE;
- dr->bRequest = 0x03; /* USB or vendor-defined request code, burst mode */
- dr->wValue = cpu_to_le16(0x0);
- dr->wIndex = cpu_to_le16(RegisterNo);
- dr->wLength = cpu_to_le16(4);
-
- /* Enter the sending queue */
- reg_queue->Next = NULL;
- reg_queue->pUsbReq = dr;
- reg_queue->urb = urb;
-
- spin_lock_irq(®->EP0VM_spin_lock);
- if (reg->reg_first = NULL)
- reg->reg_first = reg_queue;
- else
- reg->reg_last->Next = reg_queue;
- reg->reg_last = reg_queue;
-
- spin_unlock_irq(®->EP0VM_spin_lock);
-
- /* Start EP0VM */
- Wb35Reg_EP0VM_start(pHwData);
-
- return true;
- } else {
- usb_free_urb(urb);
+ if (urb = NULL) {
kfree(reg_queue);
return false;
}
+
+ reg_queue->DIRECT = 1; /* burst write register */
+ reg_queue->INDEX = RegisterNo;
+ reg_queue->VALUE = cpu_to_le32(RegisterValue);
+ reg_queue->RESERVED_VALID = false;
+ dr = (struct usb_ctrlrequest *)((u8 *)reg_queue + sizeof(struct wb35_reg_queue));
+ dr->bRequestType = USB_TYPE_VENDOR | USB_DIR_OUT | USB_RECIP_DEVICE;
+ dr->bRequest = 0x03; /* USB or vendor-defined request code, burst mode */
+ dr->wValue = cpu_to_le16(0x0);
+ dr->wIndex = cpu_to_le16(RegisterNo);
+ dr->wLength = cpu_to_le16(4);
+
+ /* Enter the sending queue */
+ reg_queue->Next = NULL;
+ reg_queue->pUsbReq = dr;
+ reg_queue->urb = urb;
+
+ spin_lock_irq(®->EP0VM_spin_lock);
+ if (reg->reg_first = NULL)
+ reg->reg_first = reg_queue;
+ else
+ reg->reg_last->Next = reg_queue;
+ reg->reg_last = reg_queue;
+
+ spin_unlock_irq(®->EP0VM_spin_lock);
+
+ /* Start EP0VM */
+ Wb35Reg_EP0VM_start(pHwData);
+
+ return true;
}
/*
@@ -236,42 +239,45 @@ unsigned char Wb35Reg_WriteWithCallbackV
/* update the register by send urb request */
UrbSize = sizeof(struct wb35_reg_queue) + sizeof(struct usb_ctrlrequest);
reg_queue = kzalloc(UrbSize, GFP_ATOMIC);
+ if (reg_queue = NULL)
+ return false;
+
urb = usb_alloc_urb(0, GFP_ATOMIC);
- if (urb && reg_queue) {
- reg_queue->DIRECT = 1; /* burst write register */
- reg_queue->INDEX = RegisterNo;
- reg_queue->VALUE = cpu_to_le32(RegisterValue);
- /* NOTE : Users must guarantee the size of value will not exceed the buffer size. */
- memcpy(reg_queue->RESERVED, pValue, Len);
- reg_queue->RESERVED_VALID = true;
- dr = (struct usb_ctrlrequest *)((u8 *)reg_queue + sizeof(struct wb35_reg_queue));
- dr->bRequestType = USB_TYPE_VENDOR | USB_DIR_OUT | USB_RECIP_DEVICE;
- dr->bRequest = 0x03; /* USB or vendor-defined request code, burst mode */
- dr->wValue = cpu_to_le16(0x0);
- dr->wIndex = cpu_to_le16(RegisterNo);
- dr->wLength = cpu_to_le16(4);
-
- /* Enter the sending queue */
- reg_queue->Next = NULL;
- reg_queue->pUsbReq = dr;
- reg_queue->urb = urb;
- spin_lock_irq(®->EP0VM_spin_lock);
- if (reg->reg_first = NULL)
- reg->reg_first = reg_queue;
- else
- reg->reg_last->Next = reg_queue;
- reg->reg_last = reg_queue;
-
- spin_unlock_irq(®->EP0VM_spin_lock);
-
- /* Start EP0VM */
- Wb35Reg_EP0VM_start(pHwData);
- return true;
- } else {
- usb_free_urb(urb);
+ if (urb = NULL) {
kfree(reg_queue);
return false;
}
+
+ reg_queue->DIRECT = 1; /* burst write register */
+ reg_queue->INDEX = RegisterNo;
+ reg_queue->VALUE = cpu_to_le32(RegisterValue);
+ /* NOTE : Users must guarantee the size of value will not exceed the buffer size. */
+ memcpy(reg_queue->RESERVED, pValue, Len);
+ reg_queue->RESERVED_VALID = true;
+ dr = (struct usb_ctrlrequest *)((u8 *)reg_queue + sizeof(struct wb35_reg_queue));
+ dr->bRequestType = USB_TYPE_VENDOR | USB_DIR_OUT | USB_RECIP_DEVICE;
+ dr->bRequest = 0x03; /* USB or vendor-defined request code, burst mode */
+ dr->wValue = cpu_to_le16(0x0);
+ dr->wIndex = cpu_to_le16(RegisterNo);
+ dr->wLength = cpu_to_le16(4);
+
+ /* Enter the sending queue */
+ reg_queue->Next = NULL;
+ reg_queue->pUsbReq = dr;
+ reg_queue->urb = urb;
+ spin_lock_irq(®->EP0VM_spin_lock);
+ if (reg->reg_first = NULL)
+ reg->reg_first = reg_queue;
+ else
+ reg->reg_last->Next = reg_queue;
+ reg->reg_last = reg_queue;
+
+ spin_unlock_irq(®->EP0VM_spin_lock);
+
+ /* Start EP0VM */
+ Wb35Reg_EP0VM_start(pHwData);
+
+ return true;
}
/*
@@ -341,40 +347,41 @@ unsigned char Wb35Reg_Read(struct hw_dat
/* update the variable by send Urb to read register */
UrbSize = sizeof(struct wb35_reg_queue) + sizeof(struct usb_ctrlrequest);
reg_queue = kzalloc(UrbSize, GFP_ATOMIC);
+ if (reg_queue = NULL)
+ return false;
+
urb = usb_alloc_urb(0, GFP_ATOMIC);
- if (urb && reg_queue) {
- reg_queue->DIRECT = 0; /* read register */
- reg_queue->INDEX = RegisterNo;
- reg_queue->pBuffer = pRegisterValue;
- dr = (struct usb_ctrlrequest *)((u8 *)reg_queue + sizeof(struct wb35_reg_queue));
- dr->bRequestType = USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_IN;
- dr->bRequest = 0x01; /* USB or vendor-defined request code, burst mode */
- dr->wValue = cpu_to_le16(0x0);
- dr->wIndex = cpu_to_le16(RegisterNo);
- dr->wLength = cpu_to_le16(4);
-
- /* Enter the sending queue */
- reg_queue->Next = NULL;
- reg_queue->pUsbReq = dr;
- reg_queue->urb = urb;
- spin_lock_irq(®->EP0VM_spin_lock);
- if (reg->reg_first = NULL)
- reg->reg_first = reg_queue;
- else
- reg->reg_last->Next = reg_queue;
- reg->reg_last = reg_queue;
-
- spin_unlock_irq(®->EP0VM_spin_lock);
-
- /* Start EP0VM */
- Wb35Reg_EP0VM_start(pHwData);
-
- return true;
- } else {
- usb_free_urb(urb);
+ if (urb = NULL) {
kfree(reg_queue);
return false;
}
+ reg_queue->DIRECT = 0; /* read register */
+ reg_queue->INDEX = RegisterNo;
+ reg_queue->pBuffer = pRegisterValue;
+ dr = (struct usb_ctrlrequest *)((u8 *)reg_queue + sizeof(struct wb35_reg_queue));
+ dr->bRequestType = USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_IN;
+ dr->bRequest = 0x01; /* USB or vendor-defined request code, burst mode */
+ dr->wValue = cpu_to_le16(0x0);
+ dr->wIndex = cpu_to_le16(RegisterNo);
+ dr->wLength = cpu_to_le16(4);
+
+ /* Enter the sending queue */
+ reg_queue->Next = NULL;
+ reg_queue->pUsbReq = dr;
+ reg_queue->urb = urb;
+ spin_lock_irq(®->EP0VM_spin_lock);
+ if (reg->reg_first = NULL)
+ reg->reg_first = reg_queue;
+ else
+ reg->reg_last->Next = reg_queue;
+ reg->reg_last = reg_queue;
+
+ spin_unlock_irq(®->EP0VM_spin_lock);
+
+ /* Start EP0VM */
+ Wb35Reg_EP0VM_start(pHwData);
+
+ return true;
}
reply other threads:[~2013-05-31 15:42 UTC|newest]
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