On Mon, Jun 09, 2025 at 09:16:00AM -0500, Prachotan Bathi wrote: > Platforms supporting direct message request v2 can > support SPs that support multiple services. > If the TPM service is sharing the SP with another service, > it could get an error code of BUSY if the other service is > in process. > This patch adds a parameterized variable (default 2000ms) > that indicates the maximum time to keep retrying for.
Patch is not a patch once it is in a Git repository. Instead: "Add a ...". > > Signed-off-by: Prachotan Bathi <[email protected]> > --- > drivers/char/tpm/tpm_crb_ffa.c | 74 +++++++++++++++++++++++----------- > 1 file changed, 50 insertions(+), 24 deletions(-) > > diff --git a/drivers/char/tpm/tpm_crb_ffa.c b/drivers/char/tpm/tpm_crb_ffa.c > index 4ead61f01299..e47e110bac9e 100644 > --- a/drivers/char/tpm/tpm_crb_ffa.c > +++ b/drivers/char/tpm/tpm_crb_ffa.c > @@ -10,6 +10,8 @@ > #define pr_fmt(fmt) "CRB_FFA: " fmt > > #include <linux/arm_ffa.h> > +#include <linux/delay.h> > +#include <linux/moduleparam.h> > #include "tpm_crb_ffa.h" > > /* TPM service function status codes */ > @@ -178,6 +180,17 @@ int tpm_crb_ffa_init(void) > } > EXPORT_SYMBOL_GPL(tpm_crb_ffa_init); > > +static unsigned int busy_timeout = 2000; > +/** > + * busy_timeout - Maximum time to retry before giving up on busy > + * > + * This parameter defines the maximum time in milliseconds to retry > + * sending a message to the TPM service before giving up. > + */ > +module_param(busy_timeout, uint, 0644); > +MODULE_PARM_DESC(busy_timeout, > + "Maximum time to retry before giving up on busy"); > + > static int __tpm_crb_ffa_send_recieve(unsigned long func_id, > unsigned long a0, > unsigned long a1, > @@ -191,34 +204,47 @@ static int __tpm_crb_ffa_send_recieve(unsigned long > func_id, > > msg_ops = tpm_crb_ffa->ffa_dev->ops->msg_ops; > > - if (ffa_partition_supports_direct_req2_recv(tpm_crb_ffa->ffa_dev)) { > - memset(&tpm_crb_ffa->direct_msg_data2, 0x00, > - sizeof(struct ffa_send_direct_data2)); > + ktime_t start; > + ktime_t stop; > + > + start = ktime_get(); > + stop = ktime_add(start, ms_to_ktime(busy_timeout)); > + > + do { > + if > (ffa_partition_supports_direct_req2_recv(tpm_crb_ffa->ffa_dev)) { > + memset(&tpm_crb_ffa->direct_msg_data2, 0x00, > + sizeof(struct ffa_send_direct_data2)); > > - tpm_crb_ffa->direct_msg_data2.data[0] = func_id; > - tpm_crb_ffa->direct_msg_data2.data[1] = a0; > - tpm_crb_ffa->direct_msg_data2.data[2] = a1; > - tpm_crb_ffa->direct_msg_data2.data[3] = a2; > + tpm_crb_ffa->direct_msg_data2.data[0] = func_id; > + tpm_crb_ffa->direct_msg_data2.data[1] = a0; > + tpm_crb_ffa->direct_msg_data2.data[2] = a1; > + tpm_crb_ffa->direct_msg_data2.data[3] = a2; > > - ret = msg_ops->sync_send_receive2(tpm_crb_ffa->ffa_dev, > + ret = msg_ops->sync_send_receive2(tpm_crb_ffa->ffa_dev, > &tpm_crb_ffa->direct_msg_data2); > - if (!ret) > - ret = > tpm_crb_ffa_to_linux_errno(tpm_crb_ffa->direct_msg_data2.data[0]); > - } else { > - memset(&tpm_crb_ffa->direct_msg_data, 0x00, > - sizeof(struct ffa_send_direct_data)); > - > - tpm_crb_ffa->direct_msg_data.data1 = func_id; > - tpm_crb_ffa->direct_msg_data.data2 = a0; > - tpm_crb_ffa->direct_msg_data.data3 = a1; > - tpm_crb_ffa->direct_msg_data.data4 = a2; > - > - ret = msg_ops->sync_send_receive(tpm_crb_ffa->ffa_dev, > - &tpm_crb_ffa->direct_msg_data); > - if (!ret) > - ret = > tpm_crb_ffa_to_linux_errno(tpm_crb_ffa->direct_msg_data.data1); > - } > + if (!ret) > + ret = > tpm_crb_ffa_to_linux_errno(tpm_crb_ffa->direct_msg_data2.data[0]); > + } else { > + memset(&tpm_crb_ffa->direct_msg_data, 0x00, > + sizeof(struct ffa_send_direct_data)); > > + tpm_crb_ffa->direct_msg_data.data1 = func_id; > + tpm_crb_ffa->direct_msg_data.data2 = a0; > + tpm_crb_ffa->direct_msg_data.data3 = a1; > + tpm_crb_ffa->direct_msg_data.data4 = a2; > + > + ret = msg_ops->sync_send_receive(tpm_crb_ffa->ffa_dev, > + &tpm_crb_ffa->direct_msg_data); > + if (!ret) > + ret = > tpm_crb_ffa_to_linux_errno(tpm_crb_ffa->direct_msg_data.data1); > + } > + if (ret == -EBUSY) > + pr_err("TPM says busy, trying again, value, ret: %d\n", > + ret); > + else > + break; > + usleep_range(50, 100); > + } while (ktime_before(ktime_get(), stop)); I'd describe the code change also in more detail i.e. what is this loop about. > > return ret; > } > -- > 2.43.0 > > BR, Jarkko
