[PATCH v2 5/9] staging: kpc2000: use atomic_t to assign card numbers.
Jeremy Sowden
jeremy at azazel.net
Thu May 16 21:38:10 UTC 2019
Previously the next card number was assigned from a static int local
variable, which was read and later incremented. This was not thread-
safe, so now we use an atomic_t and atomic_fetch_add instead.
Updated TODO.
Signed-off-by: Jeremy Sowden <jeremy at azazel.net>
---
drivers/staging/kpc2000/TODO | 1 -
drivers/staging/kpc2000/kpc2000/core.c | 7 ++++---
2 files changed, 4 insertions(+), 4 deletions(-)
diff --git a/drivers/staging/kpc2000/TODO b/drivers/staging/kpc2000/TODO
index 669fe5bf9637..47530e23e940 100644
--- a/drivers/staging/kpc2000/TODO
+++ b/drivers/staging/kpc2000/TODO
@@ -1,6 +1,5 @@
- the kpc_spi driver doesn't seem to let multiple transactions (to different instances of the core) happen in parallel...
- The kpc_i2c driver is a hot mess, it should probably be cleaned up a ton. It functions against current hardware though.
-- pcard->card_num in kp2000_pcie_probe() is a global variable and needs atomic / locking / something better.
- would be nice if the AIO fileops in kpc_dma could be made to work
- probably want to add a CONFIG_ option to control compilation of the AIO functions
- if the AIO fileops in kpc_dma start working, next would be making iov_count > 1 work too
diff --git a/drivers/staging/kpc2000/kpc2000/core.c b/drivers/staging/kpc2000/kpc2000/core.c
index eb8bac62d33d..72130a50afd6 100644
--- a/drivers/staging/kpc2000/kpc2000/core.c
+++ b/drivers/staging/kpc2000/kpc2000/core.c
@@ -1,4 +1,5 @@
// SPDX-License-Identifier: GPL-2.0+
+#include <linux/atomic.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/pci.h>
@@ -19,6 +20,8 @@
#include "pcie.h"
+static atomic_t next_card_num = ATOMIC_INIT(1);
+
/*******************************************************
* SysFS Attributes
******************************************************/
@@ -202,7 +205,6 @@ int kp2000_pcie_probe(struct pci_dev *pdev, const struct pci_device_id *id)
{
int err = 0;
struct kp2000_device *pcard;
- static int card_count = 1;
int rv;
unsigned long reg_bar_phys_addr;
unsigned long reg_bar_phys_len;
@@ -222,8 +224,7 @@ int kp2000_pcie_probe(struct pci_dev *pdev, const struct pci_device_id *id)
//}
//{ Step 2: Initialize trivial pcard elements
- pcard->card_num = card_count;
- card_count++;
+ pcard->card_num = atomic_fetch_add(1, &next_card_num);
scnprintf(pcard->name, 16, "kpcard%d", pcard->card_num);
mutex_init(&pcard->sem);
--
2.20.1
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