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PCI: endpoint: Do not reset *command* inadvertently

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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 <kishon@ti.com>
Signed-off-by: Sekhar Nori <nsekhar@ti.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
This commit is contained in:
Kishon Vijay Abraham I 2017-08-18 20:27:58 +05:30 committed by Bjorn Helgaas
parent 09232c7acb
commit 3ecf3232c5
1 changed files with 11 additions and 9 deletions
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20
drivers/pci/endpoint/functions/pci-epf-test.c
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@ -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));
}