From: Kirill Kapranov <kirill.kapranov@compulab.co.il>
To: linux-spi@vger.kernel.org, linux-kernel@vger.kernel.org,
broonie@kernel.org, l.stach@pengutronix.de
Cc: Kirill Kapranov <kirill.kapranov@compulab.co.il>
Subject: [PATCH] spi:fix IDR collision on systems with both fixed and dynamic SPI bus numbers
Date: Mon, 13 Aug 2018 19:48:10 +0300 [thread overview]
Message-ID: <20180813164810.16769-1-kirill.kapranov@compulab.co.il> (raw)
On systems where some controllers get a dynamic ID assigned and some have
a fixed number (e.g. from ACPI tables), the current implementation might
run into an IDR collision: in case of a fixed bus number is gotten by a
driver (but not marked busy in IDR tree) and a driver with dynamic bus
number gets the same ID and predictably fails.
Fix this by means of checking-in fixed IDsin IDR as far as dynamic ones
at the moment of the controller registration.
Fixes: 9b61e302210e (spi: Pick spi bus number from Linux idr or spi alias)
Signed-off-by: Kirill Kapranov <kirill.kapranov@compulab.co.il>
---
drivers/spi/spi.c | 9 +++++++++
1 file changed, 9 insertions(+)
diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
index ec395a6baf9c..97e303185d5b 100644
--- a/drivers/spi/spi.c
+++ b/drivers/spi/spi.c
@@ -2170,6 +2170,15 @@ int spi_register_controller(struct spi_controller *ctlr)
if (WARN(id < 0, "couldn't get idr"))
return id;
ctlr->bus_num = id;
+ } else {
+ /* devices with a fixed bus num must check-in with the num */
+ mutex_lock(&board_lock);
+ id = idr_alloc(&spi_master_idr, ctlr, ctlr->bus_num,
+ ctlr->bus_num + 1, GFP_KERNEL);
+ mutex_unlock(&board_lock);
+ if (WARN(id < 0, "couldn't get idr"))
+ return id == -ENOSPC ? -EBUSY : id;
+ ctlr->bus_num = id;
}
INIT_LIST_HEAD(&ctlr->queue);
spin_lock_init(&ctlr->queue_lock);
--
2.11.0
next reply other threads:[~2018-08-13 17:31 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-08-13 16:48 Kirill Kapranov [this message]
2018-08-14 14:18 ` [PATCH] spi:fix IDR collision on systems with both fixed and dynamic SPI bus numbers Mark Brown
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20180813164810.16769-1-kirill.kapranov@compulab.co.il \
--to=kirill.kapranov@compulab.co.il \
--cc=broonie@kernel.org \
--cc=l.stach@pengutronix.de \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-spi@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).