Re: [PATCH] cxl: Wrap iterations over afu slices inside 'afu_list_lock'

[Frederic Barrat]

diff --git a/drivers/misc/cxl/pci.c b/drivers/misc/cxl/pci.c
index c79ba1c699ad..28c28bceb063 100644
--- a/drivers/misc/cxl/pci.c
+++ b/drivers/misc/cxl/pci.c

@@ -1932,14 +1935,20 @@ static pci_ers_result_t cxl_pci_error_detected(struct 
pci_dev *pdev,
         *     * In slot_reset, free the old resources and allocate new ones.
         *     * In resume, clear the flag to allow things to start.
         */
+
+       /* Make sure no one else changes the afu list */
+       spin_lock(&adapter->afu_list_lock);
+
        for (i = 0; i < adapter->slices; i++) {
                afu = adapter->afu[i];
  
  		afu_result = cxl_vphb_error_detected(afu, state);
  
-		cxl_context_detach_all(afu);
-               cxl_ops->afu_deactivate_mode(afu, afu->current_mode);
-               pci_deconfigure_afu(afu);
+               if (afu != NULL) {
+                       cxl_context_detach_all(afu);
+                       cxl_ops->afu_deactivate_mode(afu, afu->current_mode);
+                       pci_deconfigure_afu(afu);
+               }

I can see you're also checking if cxl_vphb_error_detected() is called 
with a NULL afu from within the function, but why not move the call to 
cxl_vphb_error_detected() within that "if (afu != NULL)...  " statement? 
Otherwise, it looks suspicious when reading the code.


@@ -2051,10 +2067,11 @@ static void cxl_pci_resume(struct pci_dev *pdev)
         * This is not the place to be checking if everything came back up
         * properly, because there's no return value: do that in slot_reset.
         */
+       spin_lock(&adapter->afu_list_lock);
        for (i = 0; i < adapter->slices; i++) {
                afu = adapter->afu[i];
  
-		if (afu->phb == NULL)
+               if (afu || afu->phb == NULL)
                        continue;


if (afu == NULL ...

  Fred