From 3ecf3232c54cf76a21e552879285be2f313b2e06 Mon Sep 17 00:00:00 2001 From: Kishon Vijay Abraham I Date: Fri, 18 Aug 2017 20:27:58 +0530 Subject: [PATCH] PCI: endpoint: Do not reset *command* inadvertently pci_epf_test_cmd_handler() is the delayed work function which reads *command* (set by the host) and performs various actions requested by the host periodically. If the value in *command* is '0', it goes to the reset_handler where it resets *command* to '0' and queues pci_epf_test_cmd_handler(). However if the host writes a value to the *command* just after the pci-epf-test driver checks *command* for '0' and before the control goes to reset_handler, the *command* will be reset to '0' and the pci-epf-test driver won't be able to perform the actions requested by the host. Fix it here by not resetting the *command* in the reset_handler. Signed-off-by: Kishon Vijay Abraham I Signed-off-by: Sekhar Nori Signed-off-by: Bjorn Helgaas --- drivers/pci/endpoint/functions/pci-epf-test.c | 20 ++++++++++--------- 1 file changed, 11 insertions(+), 9 deletions(-) diff --git a/drivers/pci/endpoint/functions/pci-epf-test.c b/drivers/pci/endpoint/functions/pci-epf-test.c index 5cbc05a0762d..1a27d7950f2c 100644 --- a/drivers/pci/endpoint/functions/pci-epf-test.c +++ b/drivers/pci/endpoint/functions/pci-epf-test.c @@ -263,22 +263,26 @@ static void pci_epf_test_cmd_handler(struct work_struct *work) int ret; u8 irq; u8 msi_count; + u32 command; struct pci_epf_test *epf_test = container_of(work, struct pci_epf_test, cmd_handler.work); struct pci_epf *epf = epf_test->epf; struct pci_epc *epc = epf->epc; volatile struct pci_epf_test_reg *reg = epf_test->reg[0]; - if (!reg->command) + command = reg->command; + if (!command) goto reset_handler; - if (reg->command & COMMAND_RAISE_LEGACY_IRQ) { + reg->command = 0; + + if (command & COMMAND_RAISE_LEGACY_IRQ) { reg->status = STATUS_IRQ_RAISED; pci_epc_raise_irq(epc, PCI_EPC_IRQ_LEGACY, 0); goto reset_handler; } - if (reg->command & COMMAND_WRITE) { + if (command & COMMAND_WRITE) { ret = pci_epf_test_write(epf_test); if (ret) reg->status |= STATUS_WRITE_FAIL; @@ -288,7 +292,7 @@ static void pci_epf_test_cmd_handler(struct work_struct *work) goto reset_handler; } - if (reg->command & COMMAND_READ) { + if (command & COMMAND_READ) { ret = pci_epf_test_read(epf_test); if (!ret) reg->status |= STATUS_READ_SUCCESS; @@ -298,7 +302,7 @@ static void pci_epf_test_cmd_handler(struct work_struct *work) goto reset_handler; } - if (reg->command & COMMAND_COPY) { + if (command & COMMAND_COPY) { ret = pci_epf_test_copy(epf_test); if (!ret) reg->status |= STATUS_COPY_SUCCESS; @@ -308,9 +312,9 @@ static void pci_epf_test_cmd_handler(struct work_struct *work) goto reset_handler; } - if (reg->command & COMMAND_RAISE_MSI_IRQ) { + if (command & COMMAND_RAISE_MSI_IRQ) { msi_count = pci_epc_get_msi(epc); - irq = (reg->command & MSI_NUMBER_MASK) >> MSI_NUMBER_SHIFT; + irq = (command & MSI_NUMBER_MASK) >> MSI_NUMBER_SHIFT; if (irq > msi_count || msi_count <= 0) goto reset_handler; reg->status = STATUS_IRQ_RAISED; @@ -319,8 +323,6 @@ static void pci_epf_test_cmd_handler(struct work_struct *work) } reset_handler: - reg->command = 0; - queue_delayed_work(kpcitest_workqueue, &epf_test->cmd_handler, msecs_to_jiffies(1)); } -- 2.20.1